What is the Best Diamond Shapes?

The question for today is what is the best diamond shape?

diamond shapes
(The above image is a wiki commons image, a freely licensed media file repository)

I always get asked what is best, whether it is color, clarity, cut, or the best compromise, even though I always stress how everything depends on preference. When I say that, I don’t mean to shrug off the question and those of you who come to me for help will know that I try to help you establish your preferences rather than let you blindly try to figure it out on your own.

So it should seem like I would say the same about one of the most obvious things that depends on preference, the shape of a diamond. What are the things about a particular shape that would make it the best and best for what?

If we’re just going on personal taste, well then that’s not something that can be evaluated. But there are some things that we can evaluate like brilliance, fire, and scintillation. I’ve also discussed before in other articles how what is best for fancy color diamonds may not apply to colorless diamonds.

Then there are other things such as what is fashionable, and whether a shape is timeless that is more difficult to judge. There are also things like what is the shape that provides the best bang for the buck? I’ll also pose my own question, which is what is the best shape for online purchasing?

What I’m trying to get at is that there isn’t a single shape that is best for everything. That said, I’m going to tell you what I think is best for each of the following purposes.

What is the best diamond shape for light performance?

Winner: Round Brilliant Cut
image of a round brilliant cut diamond

Reasons: Preferences aside, a well-cut round brilliant diamond has by far the most brilliance, fire, and scintillation in terms of sheer quantity. On methods of measuring brilliance like the Brilliancescope, the scales have to be calibrated according to that diamond shape. This is because if a princess cut diamond was represented on the scale for a round brilliant cut, then even a well-cut princess cut diamond will still score much lower than a round brilliant diamond.

What is the best diamond shape for color retention?

Winner: Radiant Cut
image of a radiant cut diamond

Reasons: Radiant cut diamonds have more facets than a round brilliant producing more internal reflections and therefore are generally the best for color retention in a diamond.

What is the most timeless shape?

Winner: Round Brilliant Cut
image of a round brilliant cut diamond

Reasons: Ever since the first artisans started fashioning diamonds into gems, they’ve been creating diamonds into rough round shapes. The round brilliant diamond is the result of decades of innovation and is simply the most current version of a shape that has always been and will always be in fashion.

What is the shape that provides the most bang for the buck?

Winner: Princess Cut
image of a princess cut diamond

Reasons: The shape of a princess cut fits more with the natural octahedral shape of most diamond rough material. For some pieces of rough, if a cutter chose to cut 2 round brilliants, you would get one larger and one smaller diamond. But if he chose to cut 2 princess cuts, then he might get two medium sized diamonds that most of the time will fetch a better overall price. Even though the price per carat for princess cuts is lower, the better utilisation of the rough material means there is a higher rough yield.

What is the best shape for men?

Winner: Cushion Cut
image of a cushion cut diamond

Reason: No particular reason, just the shape that came up in a survey I did. By no means statistically valid, but over 90% chose a cushion cut. Also, the definition of a cushion cut is fairly broad and almost any square shape with rounded corners can be properly considered a cushion cut.

What is the best shape for short fingers?

Winner: Marquise Cut
image of a marquise cut diamond

Reason: A marquise maximises the length of a diamond per carat weight and therefore will make your fingers look longer. You want to avoid shapes like squares and rounds that will have the opposite effect.

What is the best shape for long fingers?

Winner: Princess Cut
image of a princess cut diamond

Reason: A princess cut can have a length to weight ratio of 1:1 making it a perfect square. Although almost any shape will look good on long slender fingers, you will want to avoid shapes like marquises, pears, and ovals that will make your fingers look even longer.

What is the best shape for larger sized stones?

Winner: Emerald Cut
image of a emerald cut diamond

Reason: Very large round brilliant diamonds can start to look tacky and fake. They can also be very flashy and not appropriate for any venue. With emerald cuts, you’re not constrained in length to weight ratios. Their step cutting means that their beauty comes not from a sheer quantity of light return, but rather from a huge display of a broad fire flash when viewed at just the right angle. These diamonds have to be big before their true beauty is unleashed.

What is the best shape for investment?

Winner: Round Brilliant Cut
image of a round brilliant cut diamond

Reason: In general if you don’t know what you’re doing then diamonds are bad investments. But if we’re talking about investment, you want a diamond that has the most liquidity and that means getting a diamond with a shape that is most sought after. A good place to start is to look at what is available for sale. Aside for in fancy colored diamonds, round brilliant cuts are by far the most popular diamond shape and therefore make the best investments. Remember, that I am not an investment advisor and what I have said here is not meant for you to take as any sort of investment advice.

What is the best shape for online purchasing?

Winner: Round Brilliant Cut
image of a round brilliant cut diamond

Reason: The round brilliant cut diamond is the only diamond that has an undisputed set range of proportions that give the best light performance. This is the reason no other diamond receives a cut grade from GIA. There is also more information available regarding round brilliant cuts and there are many more experts and prosumers that know more about round brilliant cut diamonds than another other cut. For online assessment, we can use idealscope images, ASET, and hearts and arrows images for round brilliant diamonds whereas for other shapes, generally only an ASET is used and interpretation is subjective and difficult.

Conclusion

So whether you agree or disagree with the reasons I have given, I have showed you that there is a best diamond for every purpose. In my opinion, if I had to pick a diamond shape which is best overall, it would have to be the round brilliant cut; it is a remarkable balance of faceting and angles that makes it a very unique shape to me despite it’s popularity. If you are undecided then you should definitely consider a round brilliant cut as the standard, especially if you are thinking about purchasing online. If you can think of other purposes that you would like to know what diamond shape is best or if you have your own ideas for what is best, then please leave a comment!

Yaw, Twist, Distortion, and Azimuth Shift

Welcome to the sixth tutorial in prosumer level 3 on facet yaw. The aim of this tutorial is to explain what yaw is, why it occurs, how it occurs, how to detect it, and how it affects the appearance of a diamond. I will also try to clear up the confusion regarding this topic in relation to the terms yaw, twist, distortion, and azimuth shift.

What is Facet Yaw?
Facet yaw is a type of facet distortion that can occur either through poor cutting or tricky cutting. The technique of yawing a facet can be used to tweak the diamond’s proportions while maintaining the lab-graded symmetry grade. Like painting of the girdle, yawing is therefore potentially a swindling strategy. In the industry, the term ‘cheated’ is sometimes used referring to the facet where swindling strategies was used.

Yaw is a confusing term primarily because it is difficult to visualise; and secondly because of its naming. In science, yaw refers to a rotation in the corresponding z-axis. Those of us who are familiar with airplanes or gyroscopes will know that the other axes are named pitch (y-axis) and roll (x-axis).

rollpitchyaw
(This is a picture from the Wikimedia Commons, a freely licensed media file repository.)

Lets get it clear straight off the bat that facet yaw in diamonds does not exactly mean that the facet rotates in a corresponding axis. It is also not helpful to think that yaw refers to curved facets. In a yawed facet, the slope of the facet varies but it is not really a curve, as a curve requires a constant variation of the slope across the facet, whereas a single change in slope can cause a yawed facet.

To understand yaw, we need to know a bit about how a diamond is polished. Diamond facets are usually polished with the cutting wheel spinning in the east west direction (relative to the facet) and the diamond is moved into contact with the cutting wheel where material is removed normally from a north south direction (north being towards the crown side). The starting point is usually at the girdle cutting either north or south.

Yaw is sometimes referred to as a twisting of the facet. Facet indexing is another way to twist the facet and it can easily be confused with yaw. We discussed upper and lower girdle indexing in Prosumer Level 2 so you should be familiar with the term. Both indexing and yaw may appear to twist the facet, but it is important to understand that indexing is not yaw. To clarify, here is how I understand the terminology.

•    Distortion encompasses any misalignment or twist
•    Twist can be either due to indexing or yaw

Yaw occurs when the graining of the diamond is such that it is impossible to cut in the north south direction and the cutter is forced to take material away from the east west direction.

NSEWfaceting
(This image is courtesy of Whiteflash, used with permission.)

This marks the most important difference between yaw and indexing, because indexing is still cutting from the north south direction. The problem cutting from the east west direction is that it causes one side of the facet spends a bit more time in contact with the cutting wheel.

flatnotflat
(This image is courtesy of Whiteflash, used with permission.)

One side of the facet has more material removed from it causing the facet angle to change. At the new angle, the facets would normally not meet nicely at the girdle. The result of the cutter’s techniques to correct the facet meet-points causes what is referred to as ‘azimuth shift’.

Now the azimuthual direction is also known as the ‘hoop’ or circular direction; that is the direction you would be walking if you were walking in a circle. An azimuth shift means that if the facet length is kept the same, then the facet will be either shifted into the diamond or away from the girdle. In reality, instead of actually shifting the facet, the shifting manifests itself as a change in slope. The cutter will try to hide this as much as he can by gradually changing the slope. It is basically saying that the original facet is split into several facets so that some of these new facets end on a point, which is on one of the other new facets, rather than extending all the way to the girdle.

This technique can be effective to hide the effect from casual observers and from digital scanners that don’t check for it. Suffice to say it takes a tremendous amount of skill in order to hide this effect because it involves yawing of at least three of the lower girdles in order to ensure that the meet-point-symmetry remains intact.

I can finally bring it altogether and form the definition of yaw in diamonds. Yaw is the observable result of azimuth shift. It is a complication of the cutting process that leaves a defect, which in the most minor of cases can only be detected in a properly taken H&A image. The resultant effect would look like the facets have excellent meet-point-symmetry but in fact the physical and therefore optical symmetry has been compromised. A further effect of yaw is that a part of the yawed facet has to be cut further into the girdle than originally in order to hide the other meet points and this has the effect of making the girdle thinner at the yawed facet.

Visually, the appearance of minor yaw is difficult to detect from a face-up position. If we take a yawed pavilion facet for example, theoretically the yawing will cause a different slope producing a slightly different light return signature. I doubt this will be noticeable though, even in an idealscope image. However, because three other lower girdles have to have their slopes varied, the lower girdle lengths will be affected the most. This could have the effect of tilting some of the hotspots, but this is not a reliable method to detect yaw, as too much effort has to go into making sure the viewing environment is level.

By far the best way to detect yaw is using the hearts image. As we learned from the previous tutorial, the Vs in a hearts image indicate variation of the lower girdles and uneven Vs will indicate even the most minor effects of yaw. Also, because the hearts are formed from two different pavilion facets, any variation in the pavilion facets will cause misaligned hearts.

yaw diagram
(This image is courtesy of Whiteflash and John Pollard, used with permission.)

Yaw is probably not a concern for consumers of diamonds that are marketed as near H&A. But for those of you who are seeking an H&A, it is important for you to be aware of this defect. By choosing a diamond that has no yaw, you are essentially choosing the top 10% of all super-ideal diamonds in the world.

Camera Tilt
Now this brings me onto the final point, which is camera-tilt. This will not be new for those who have read my Crafted by Infinity review.

The following images demonstrate what I mean by camera tilt.

camera-tilt
(This image is courtesy of Infinity Diamonds, used with permission.)

You can see how just 1 degree of tilt in any part of the photography setup (camera lens, body, tripod, table, floor) can create the above illusion. This means we cannot jump to conclusions regarding yaw just because we see some distortion. Please also note that if the setup is perfectly level, the only other thing that can cause this effect is tilt of the table facet. A 1-degree tilt will be caught by the lab symmetry grade so you will know you’re dealing with camera-tilt if the diamond has an excellent symmetry grade.

I have found the best way to detect any yaw that is not an illusion is to find the line of symmetry in the diamond. Once you identify the line of symmetry, you can eliminate the effects of one axis of tilt. Then you can check whether all the V’s are still a bit smaller on one side of the imaginary line of symmetry than the other to determine whether there is tilt in the other axis. Any distortion of the V’s that cannot be explained consistently by camera-tilt will have to be assumed to be yaw.

Camera-tilt not only causes the illusion of yaw, but also produces what appears to be clefs in between the hearts. You can detect ‘fake’ clefs by noting how close the heart is from the V. If there are hearts in the image that show no clefs but are further from the V, yet hearts that have clefs are closer to the V, then you know that the clefs are illusions from camera-tilt.

Conclusion
We now know that yaw in diamonds is the observable effect of azimuth shift. It occurs because of complications in the cutting procedure due to irregular graining. The best way to detect it is to look at a hearts image and look for distortion of the Vs and misalignment of the hearts. However, it is important to bear in mind the effects of camera-tilt. The presence of minor yaw does not affect the face-up appearance of diamonds that much and should not be a main consideration for those seeking diamonds that are marketed as near-H&A. But for those seeking the best-of-the-best in terms of the optical symmetry that you get with a true H&A diamond, then you should look for a diamond without the presence of yaw. If you are looking for a true H&A diamond and are struggling with the photographs you see online, then please feel free to send me an email and I will do my best and try to help you out.

Virtual Facets

Introduction to Virtual Facets
This is the penultimate tutorial in Prosumer Level 3 and today we are going to be discussing the topic of virtual facets, which is what I consider to be the current pinnacle of diamond optics. I will explain what they are, how we have been using them, and how they affect the appearance of diamond.

I have mentioned the concept of virtual facets several times in my previous tutorials and so you should already know that it is simply a term given to the reflections of real facets. They are called ‘virtual’ because when we look at them, they appear as though they are individual facets handling light differently from its neighbouring virtual and real facets.

The best-known virtual facets are the arrows in a hearts and arrows diamond. We now know that the patterning of the arrows is created using the reflection of the pavilion mains. We have been utilising virtual facets and how they behave, face-up in a well-cut diamond, to identify certain features in light performance images. The point of this is to get you to familiarise yourself with what we are talking about and to show you that you already know a bit about virtual facets. The only difference now is that we are not only going to be considering the face-up view because the virtual facets of a diamond change when you tilt a diamond.

Now virtual facets affect the diamond’s optics because they are what we see at any given time. If the real facet is leaking, then the virtual facet will leak light, but the virtual facet can be leaking light even when the real facet is returning light. Understanding virtual facets will allow you to evaluate a diamond not just from the face-up view, but also through all the tilt angles. If you pick up a diamond ring in a jewelry store and you start tilting it, a diamond that we would normally call a steep-deep would seem to be returning a great deal of fire. This is because as you tilt the diamond, the angles of the crown and pavilion facets change and instead of leaking, it will return light. Whenever a virtual facet is returning colourful flash, they are commonly referred to as giving off an ‘event’. Because steeper facets are often larger, their virtual facets also become larger and you observe an apparently larger event. The point to remember is that the angle at which you view the diamond is important and that this is one of the ways a jewelry store can be designed to enhance the look of certain diamonds we normally reject.

A large virtual facet naturally returns a greater amount of light to your eye, whether you perceive it to be white light or a colourful flash. In terms of fire, it is the larger events that we consider to give off bolder flashes. Apart from the size of the virtual facet, we also want to know the number of virtual facets. Logically, there is an inverse relationship between the number and size of virtual facets for any given area. We can say that a greater number of virtual facets mean that there is in terms of shear quantity, more scintillation.

Other things we want to consider are the pattern of the virtual facets. In previous tutorials we looked at the contrast pattern of the diamond focusing on the bright and dark areas. Dark areas could be either virtual facets that are reflecting head shadow/body obstruction or alternatively are leaking light with a dark background. When we talk about virtual facets, we are going to be talking more about fire and scintillation rather than brightness and contrast. There is some overlap here because in general, we are looking for something that has a well-balanced distribution whether it is a balance between dark and bright reflections, or the balance between large and small flashes of color.

There is however a major difference, which I mentioned at the beginning of the tutorial and that is when we look at fire and scintillation, we want to look at not only the face-up position but through all the tilt angles. Now in theory, a diamond with perfect optical symmetry will give off the most balanced fire and scintillation. But apart from balance, we are looking for that even distribution of fire throughout the diamond. Here is where hearts and arrows come in. Now personally I am not a huge advocate of perfect hearts and arrows or what you would consider a purist, although I appreciate how special a truly perfect H&A is. But many people have told me that light performance is the most important aspect to them yet they fall short of requiring perfect H&A in their diamond search.

Virtual Facets in Hearts and Arrows Diamonds
A proponent of H&A would argue that H&A is actually very important to light performance, in particular for fire and scintillation. This is because hearts and arrows produce the least number of virtual facets in a standard 57-facet modern round brilliant cut. Remember that the small number of virtual facets in an H&A mean that the size of the virtual facets are larger. Apart from being a matter of preference, there are advantages to having larger virtual facets. For example, in a large diamond, you may notice many large and small events that all register as a flash to your eyes. However, in smaller diamonds, you may only get a few large events and the others are small events. Many more are events that are so small that they do not even register as a flash to your eyes. A virtual facet that returns a flash that registers to your eyes is what is called an effective virtual facet. Conversely, a virtual facet that doesn’t register a flash is known as an ineffective virtual facet.

Ineffective virtual facets are the reason why if you look at melee type diamonds that have a full cut, then these diamonds do not really have that much sparkle to them. The entirety of the diamond appears bright for reasons that I will come to when we talk about cones below. However, there is no sparkle because the virtual facets are too small to produce a flash. This is why if you want a pavé ring with small melee diamonds to sparkle, it may be better for your personal preference to find melees that have an eight-cut. An eight-cut diamond has fewer real facets and produces fewer numbers of virtual facets that are consequently larger. Just bear in mind that diamonds that are optimised for fire rarely photograph well.

Sometimes, a diamond is designed to have a large number of virtual facets. The perfect example is a crushed-ice look cushion cut. The crushed-ice appearance is a result of a chaotic patterning of many virtual facets that are created by cutting in a way to increase the internal reflections within a diamond. We have previously discussed that increasing internal reflections increase color entrapment and that is why color diamonds are more often than not cut into fancy shapes such as radiant cuts that have a large number of virtual facets. When a diamond has a chaotic patterning of virtual facets, there is no easy way to predict whether these virtual facets are returning light or are leaking light without using Diamcalc to model the entire diamond, which also has its limitations. That is why I would consider a diamond that has more virtual facets such as a crushed-ice looking diamond at a higher risk of having more light leakage. On the other hand, a diamond with more virtual facets can have a chance of being brighter than the background in darker situations because the diamond gathers light from more different places.

Because fancy shapes are not cut to maximise performance, they typically have larger numbers of virtual facets compared to round diamonds. They also have more types of facets and therefore a more complicated patterning of virtual facets. In other words, fancy shape diamonds tend to have more internal reflections and this explains why they are less brilliant than the modern round brilliant diamond. For this same reason, fancy shapes are better for color retention. Also, because of the chaotic patterning, the only way to properly assess a colored diamond is by visual inspection. Fortunately, an ASET viewer can make this task easier by helping us discern the patterning and distribution of light and also tell us how the diamond handles light.

Now the reason why virtual facets can sometimes be so small that they become ineffective is because of dispersion. We have talked about dispersion before and how larger facets increase dispersion in any particular diamond. The same is true for virtual facets. A small virtual facet has less dispersion and this means that when white light is dispersed into the spectrum colors, it fans out more narrowly as it leaves the diamond.

Cones
We now enter the area of optics.

When we see white light, the reason is because our eyes can recombine the colors of the spectrum as it enters through our pupils. When we see a flash of color, it is because the light is fanned out so large that our pupils ‘clip’ the light so that we cannot see the entire spectrum of light in order to recombine white light. We therefore only see a part of the spectrum that manifests itself as a colourful flash. This is why when we look at a diamond in a bright room, we are more likely to see color in a diamond because our pupils are contracted. Conversely, in the dark when our pupils dilate, we are less likely to see the color in a diamond. But this is only one of the reasons why we perceive color better where it is bright.

pupil-dispersion
(The above images are courtesy of John Pollard, used with permission.)

Our eyes have two kinds of color receptors, rods and cones. Rods are the receptors that detect blacks and whites and cones are the receptors that detect color. When it is dark, our brains tell our eyes to switch to using more rods than cones because cones require a lot of light in order to function. It is the combination of using fewer cones and clipping less light that we perceive less of a diamond’s color in dimmer conditions. Remember that the above discussion is independent of the type of light source, which also plays a part in a diamond’s fire so please don’t be confused by thinking that because you notice more fire in your diamond in dim situations, such as under incandescent lighting, that dimmer conditions are more favourable for fire.

Conclusion
To conclude, a virtual facet is a reflection that behaves just like a real facet. Virtual facets can therefore leak light, return white light, or return a colourful flash. Virtual facets can either produce large flashes of lights known as large events or small flashes of light known as small events. A virtual facet that produces an event that your eyes can register as a flash is an effective virtual facet. An ineffective virtual facet means that it is so small that the light being dispersed from the diamond recombines into white light before entering your eyes. An H&A diamond can produce a better pattern in terms of its balance of large and small events. Melee diamonds that are eight-cut have fewer virtual facets that increase the number of effective virtual facets increasing fire and sparkle. However, melee diamonds that are full-cut have a better balance of smaller virtual facets and coupled with ideal proportions will generally be brighter than the eight-cut.

Understanding H&A Formation

The aim of this tutorial is to discover how the hearts and arrows patterns are formed in a super-ideal diamond. Understanding hearts and arrows formation allows you to have a better appreciation of the cutting precision that is required to form it. I will take you through exactly which facets are responsible for which part of the pattern. If you are seeking an H&A for its perfection, then it this is important for you to be able to analyse the H&A images to determine in detail the proportions and minor defects that many diamonds have.

Crown and Pavilion Facets
eightcutha

The images above are what the hearts and arrows images would look like for a single or ‘eight’ cut diamond – that is with only the crown, pavilion, table, girdle, and culet formed. The wire mesh shows the faceting of the eight crowns and eight pavilions. The arrows image is taken from the crown view and the hearts image is taken from the pavilion view. An H&A viewer returns white from the top and shades of red from the sides; light leakage is black. The shades of red are not important because we are not looking at light performance.

In the crown view, you can easily see through the table into the pavilion facets that are returning light from overhead. You can also see the table reflection in red. The white triangles that you see are reflections of part of the pavilion facet from the opposite side of the diamond, which are inverted. The red areas on the sides of the crowns are returning light from the side of the diamond.

In the pavilion view, the real pavilion facets are more or less acting as the crowns would, and are returning light from the side of the diamond so they are in red. You can see the reflections of the pavilion facets on the opposite sides of the diamond; again they are inverted but they are red because the the pavilion facets are angled an meet at a point, the culet.

Adding the Lower Girdles
eight cut h&a

The images above are the hearts and arrows images after the lower girdles are added. You can see that it is the lower girdles that primarily create the hearts and arrows effect. The arrows image is actually made up of a combination of a real pavilion facet and a virtual facet, which is the reflection of the opposite pavilion facet. The lower girdles shape the real pavilion facets into the arrow shafts. The lower girdles also shape the pavilion reflections into the arrow heads.

More interesting is how the hearts are formed.

hearts cutting

It takes two pavilion mains together to make up a single heart. The image above demonstrates the formation of the 6:00 heart.

hearts formation

Take a closer look at a single side of a heart; it is actually the reflection of the pavilion facet as seen from that lower girdle. You can also see that the real lower girdle facets split the hearts from the Vs. This explains why shorter lower girdles produce hearts that are closer to the Vs. Lower girdles that are shorter than 75% will have hearts that touch the Vs and are a cause for rejection for H&A purists.

open hearts
(This image is courtesy of Good Old Gold, used with permission.)

Lengthening the lower girdles has the opposite effect of a wider gap between the heart and the V. If the lower girdle length is above 78.5%, then there will begin to be clefts in between the hearts because the reflections of the pavilion mains are also more angled in towards each other. The existence of clefts are also a cause for rejection for H&A purists. You can see how the popoularisation of H&A has helped precision diamond cutters because it limits the lower girdles to a narrow range between 75 to 78.5%. To put it in perspective, the variance in the lower girdle angle for a range between 75 to 78.5% lower girdle length is less than one degree.

Star and Upper Girdle Facets
full cut h&a

The images above show the typical H&A images you see in a full-cut round brilliant diamond with a wire mesh showing the real facets. You can see how the brillianteering of the upper girdle and star facets changes the shape of the table.

arrows formation
(This image is courtesy of Good Old Gold, used with permission.)

The reflection of the lower girdle seen through the stars is actually quite similar to the arrows that the reflections of the pavilion mains seen through the crown, just reversed. Hopefully you can now spot for yourself that the hotspots are simply reflections of the pavilion mains adjacent to the lower girdle reflection seen through the stars. You also can see how lengthening the stars reveal more of the lower girdle and pavilion main reflections leading to larger hotspots. The M’s that can be seen in the crowns and the upper girdles are actually the many virtual facet reflections of the lower girdles/pavilion facets.

upper star h&a

On the hearts image, the star facets are responsible for flattening out the tips of the hearts and finally adding the upper girdles round off the edges of the table reflection (off the crown facets) and complete the patterning of the H&A image.

Conclusion
You should now have a much better understanding of how a hearts image can help you identify the minor defects in a diamond. Misaligned arrows mean that opposing pavilions are not symmetrical. Hearts that are not symmetrical means there is asymmetry in the pavilion mains. Misaligned hearts and distorted V’s indicate that there is some misalignment of the lower girdles. A cleft in between the hearts and the gap between the heart and the V can help determine the length of the lower girdles. We now know that basically all the hotspots are simply reflections of the pavilion mains and all the M’s are reflections of the lower girdles. We also know that any variation in the width of the tips of the hearts indicate variation in the star facets, and any imbalance in the edges of the hearts image indicates variation in the upper girdles.

Crafted by Infinity Review

Crafted by Infinity is a brand that is manufactured by Infinity Diamonds, a small cutting house with the aim of cutting the highest quality diamonds in the world. Rather than selling their brand themselves, these diamonds are sold exclusively by several dealers. There are some immediate advantages to this. The first that is evident to me is that the quality of the product will likely be higher because of the additional vetting process by the nature of having more parties involved. Second is that the cutting house is more focused on what they specialise in and don’t have other internal pressures to save costs by retaining carat weight on their diamonds. Third is that the brand probably has some kind of unique look about them that can be immediately recognisable.

As I was browsing the Crafted by Infinity website doing this review, I came across an important point they state on their website; that is, cut grading is in its infancy and unlike color or clarity, what is graded excellent today may not be excellent in a few years time. This can have serious implications on the future value of the diamond you purchase. Of course, you don’t have to purchase an Infinity diamond in order to protect yourself, that is what Prosumer Diamonds is here for. Also, there are many reasons why precision cutting and H&A may never become a recognised superior cut grade by the major labs.

Crafted by Infinity makes an effort to market their diamonds as ‘superideal’. They claim that their diamonds are cut to such rare standards that it is more rare than D color and IF clarity. They make a point to say that they cut ‘only’ 1000 diamonds per year. They say that their brand’s best feature is “Flawless Cut”, which is the only cut grade they aspire to. I have no problems with most of these claims, as they are mostly true. For example, I know that superideal cut diamonds are in the top 1% of all diamonds cut and D-E color diamonds make up around 2% of diamonds.

Although there is also no standard for what a flawless cut is, we do know that most H&A diamonds have minor defects. Diamonds that have several minor defects or a single major defects will not be considered H&A by some vendors. So I can tell how strict a H&A vendor is by how many defects they accept as part of their brand.

I spoke with Paul Slegers, Managing Director at Infinity Diamonds, and he explained to me what they mean when they say their diamonds have a flawless cut is that their standard of flawless craftsmanship is that no defects can be seen under 10x magnification. I think this is fair, considering that GIA grades all other aspects of the diamond under the same magnification power. This is a point that I will bear in mind when I come to reviewing their images below.

On the Infinity Diamonds website, you will find a link to their dealers around the world. As I look through the list, the two vendors I have heard of already are High Performance Diamonds by Wink Jones and Diamonds by Lauren by David Friedlander. Basically, each online vendor will carry the same list of Infinity diamonds for the same price, using the same search engine. Please note that only some vendors offer a 5% wire discount and I would recommend High Performance Diamonds because Wink is one of the more active experts and it won’t hurt to see if he will give you an additional Pricescope discount. The search engine is pretty basic and you can only choose between round and princess cuts, the 4C’s, and price. Lets see if there really isn’t any need to have advanced search functions.

I first notice that there are only about 100 diamonds in total, but I managed to find 6 G to H VS2 diamonds to compare.

It takes a little bit more time than usual to get to the useful information on Infinity’s system. The table, depth, pavilion, and crown information is only visible if you click on a button labelled ‘expert details’. Even then, there isn’t any immediate information about the lower girdle length or girdle thickness information and you have to find that information on the AGS lab report yourself. As far as I can tell, all of the Infinity diamonds are graded by AGS, which has both its positives and negatives, as you will know from previous tutorials. One positive is that Infinity provides AGS lab reports that also have the hearts images. But be aware that the ASET images seen in the AGS lab report is generated digitally and contains potential scanning errors such that it is not a true representation of the diamond but rather a good approximation that cannot replace the actual images.

I collected the data from the 6 diamonds and put in them in the table below:

Infinity Table

As the prices and availability of these diamonds will inevitably change, please visit the source directly for the most up-to-date prices. They also have higher quality images.

1.03 Ct. G VS2
1.09 Ct. G VS2
1.18 Ct. G VS2
1.01 Ct. H VS2
1.05 Ct. H VS2
1.09 Ct. H VS2

All of these diamonds have thin to medium girdles, which helps the 1.01 ct stone to reach that 6.5mm mark that is expected of an ideal 1ct diamond. Apart from this, the only things I can comment on is that the table size is generally between 55% and 57% and each one has a total depth under 62%. From the small sample above, it does not seem like there is a specific pavilion angle that these diamonds are cut to like the Brian Gavin Diamonds stones. This is a positive for those who are looking to squeeze the last bit of carat weight into the diameter of the diamond. The theme of spread continues as I look at the crown facets. All of them are between 34 – 34.5 degrees and this means two things – better spread and increased light return under the table.

Finally I have a look at the lower girdle facets and all but 2 of them have a 78% lower girdle length with the other two 75% and 77%. Although probably not representative of all of their diamonds, I can only conclude that there is not a single contrast pattern of the arrows on all Infinity diamonds and you still have that freedom to choose your preference. It also seems like the lower girdle facets are cut so that they are just under 78.5% lower girdle length in order to achieve a hearts pattern that does not have a clear clef in the middle of the hearts.

So far all of the numbers look good right? Well we know that these numbers only tell half the story so lets get into the hearts image and idealscope images to see how the Crafted by Infinity diamonds hold up to their reputation.

Light Performance

Here are the 6 idealscope images.

table of idealscopes
(The above images are courtesy of Infinity Diamonds, used with permission.)

From a light performance point of view, all of the diamonds above seem to look good in their idealscopes with no visible leakage under the table. The light return also seems very balanced throughout the diamond. Although it may seem like there is no leakage in the upper girdles and that there may be some crown-only painting, it is not the case here as I think this is more to do with photography.

actualinfinity    Eightstar
(The use of the above images are courtesy of Infinity Diamonds and Good Old Gold respectively, used with permission.)

For now, you can find the actual picture here and an example of the idealscope from an Eightstar diamond here, scroll 3/4 way down the page.

You can see from the actual image of the 1.03 GVS2 that there is some contrast in the upper girdles, which is eliminated when the girdle is painted. Also compare the idealscope images of the 1.03 GVS2 with the Eightstar diamond that has crown-only painting. You can see that the idealscope images of the Infinity diamonds are clearly not the same.

Optical Symmetry

table of hearts
(This image is courtesy of Infinity Diamonds, used with permission.)

At first glance, the rest of the diamonds seem to have some obvious defects. But it turns out that most of these defects are actually illusions and I would like to thank both John Pollard and Paul Slegers for taking the time and effort to go out of their way to educate me further on the photography issues discussed below. Let me explain with an illustration. The first row of images are computer simulated images of the actual diamond.

camera-tilt
(The above images are courtesy of Infinity Diamonds, used with permission.)

You can see how just 1 degree of tilt in any part of the photography setup (camera lens, body, tripod, table, floor) can create the above illusion. This means we cannot jump to conclusions regarding yaw just because we see some distortion. Please also note that if the setup is perfectly level, the only other thing that can cause this effect is tilt of the table facet. A 1-degree tilt will be caught by the lab symmetry grade, and as Infinity diamonds are all graded excellent symmetry by the AGS, the issue here is not a tilted table facet.

Apart from the first diamond (1.03 GVS2), all the diamonds in my sample seem to be affected by tilted photography. Although this isn’t particularly helpful to us discerning prosumers, it just takes a little more effort to recognise the effect of camera-tilt in photographs. If possible, you should always go and see these diamonds for yourself.

Having studied the above photographs in depth, I have found the best way to detect any yaw that is not an illusion is to find the line of symmetry in the diamond. Once you identify the line of symmetry, you can eliminate the effects of one axis of tilt. Then you can check whether all the V’s are still a bit smaller on one side of the imaginary line of symmetry than the other to determine whether there is tilt in the other axis. Any distortion of the V’s that cannot be explained consistently by camera-tilt will have to be assumed to be yaw, or ‘twist’, which is distortion of the diamond in the azimuth.

Camera-tilt not only causes the illusion of yaw, but also produces what appears to be clefs in between the hearts. You can detect ‘fake’ clefs by noting how close the heart is from the V. If there are hearts in the image that show no clefs but are further from the V, yet hearts that have clefs are closer to the V, then you know that the clefs are illusions from camera-tilt. Looking at the hearts images of the 6 sampled diamonds, I can conclude that all the larger clefs that can be seen are illusions due to camera-tilt.

So now let me get to the minor defects that I see that are not apparently caused by camera-tilt. I will start with the first diamond in the table, which is the 1.03 GVS2. Take a look at the heart at the 12 o’clock position, this heart is slightly smaller than most of the rest. You can see that the gap between the heart and the V is bigger than all the rest apart from the opposing heart. The idealscope tells the story more clearly the larger hotspot in between the second and third arrow is a clear indicator of a smaller heart. In the case of this diamond, the opposing heart appears to be also slightly smaller. Having dealt with camera-tilt above, I would not rule out potential photography issues as the cause of this, but as it stands, this diamond misses the mark as a true H&A in my books.

Now take a look at the fifth diamond, some of the hearts look like they are touching the V’s indicating shorter lower girdles. Correcting for camera-tilt, it seems like the hearts will just barely not touch the V’s. I’m pretty sure that this is the diamond with the 75% lower girdle length as stated on the certificate. Although not a cause for rejection, this may be a consideration for you if you are a H&A purist. Finally, although not a cut issue, I also noticed an inclusion that reflects around the pavilion in the third diamond, what is known as a ‘reflector’. This is not good for a VS2 diamond and you can definitely find better.

Having considered all the information, and inspecting the hearts images of all 6 diamonds thoroughly, I have come to the conclusion that notwithstanding the camera-tilt, it is apparent to me that at least 5 out of the 6 diamonds are cut to the highest level of precision and are deserving of the super-ideal qualification.

Price

The price of a Crafted by Infinity diamond carries a price premium that is expected of a top-of-the-line super-ideal H&A brand. A comparison with the online vendors that move far greater volumes of diamonds just doesn’t seem fair. Remember that Infinity Diamonds primarily targets showroom clientele and viewed in this light, their prices are justified and even provide greater value than other popular brands (Tiffany, Cartier, Hearts on Fire, etc). I’m just glad to see that outfits like High Performance Diamonds are still providing an opportunity for online consumers access to these diamonds.

Value Added Services

As Crafted by Infinity is not a retailer themselves, each of their dealers will have their own value added services so I will not go over them here. There is one interesting value add that Crafted by Infinity provides and that is their ‘Meet the Cutter’ events. This gives a chance for any Infinity owner to go to any one of their dealers who is holding one of these events where they get to meet the person who cuts their diamond. Diamond prosumers should find this an interesting and valuable chance to learn about diamonds so if you’re lucky enough to be in the area of one of the dealers, then this may be something worth your consideration.

Conclusion

I had a great time doing this review, not only did I learn a lot more about Infinity Diamonds, which I hope I have successfully conveyed on to you, I also learned a lot about how market trends and photography has changed the diamond industry.

I found that the diamonds I reviewed had excellent spread for a well-cut diamond so you will get a good sized diamond for the stated carat weight. If spread is important to you and you want a super-ideal diamond then Crafted by Infinity may be a good option for you. The diamonds I reviewed also tend toward the brighter side of my recommended range of proportions rather than the dispersive side. Their excellent spread is due to their attention given to the thin to medium girdles, close to 56% table percentage, 40.7-degree pavilion angles, and close to 34-degree crown angles.

The only problem that I identified with Infinity Diamonds is with their photography setup, as the camera-tilt makes it harder for consumers to make online purchasing decisions. If you need help interpreting any of their images online, please feel free to send me an email and I will try my best to help you out. I hope that Infinity Diamonds will be able to one day improve the quality of their photography.

I want my readers to appreciate the investment that is needed in order to produce high quality pictures and that it can be a burden on a small cutting house such as Infinity Diamonds. If you have any concerns regarding optical symmetry, Wink Jones at High Performance Diamonds, who carries the Crafted by Infinity brand has a ‘See It To Believe It” (SITBI) program where you can see the diamond for yourself before you buy it.

The bottom line is that if you’re looking to seek comfort from a reputable brand name who produces some of the best looking precision cut diamonds in the world, then you should consider a diamond that is Crafted by Infinity. I recommend those seeking a Crafted by Infinity diamond to demand nothing short of top-of-the-line optical symmetry that is expected of their cutting house and brand.

Fancy Color Diamonds and Color Entrapment

Welcome to the second tutorial in Prosumer Level 3 on Fancy Colored Diamonds (FCDs) and color entrapment in colorless diamonds. This tutorial is meant for you to understand more about diamond color and to introduce you to the world of fancy colored diamonds. Even if you are not in the market for a fancy colored diamond, it may still be useful for you to understand a bit about how they are cut because some of the concepts here also apply to colorless diamonds.

Fancy Yellow Color Diamonds
In my basics tutorial on diamond color, I told you how colorless diamonds are graded from D-Z, and they are also known as the Cape series diamonds. I also told you how most of these yellow diamonds are best described to have a yellow tint. But toward the end of this scale, the diamonds begin to have obvious yellow body color. You will also be aware that the price per carat is lower the lower you go down in the D-Z scale. But fancy yellow colored diamonds carry a significant price premium over colorless diamonds. This opens up the possibility of bargain hunting for colored diamonds that are not ‘true’ fancy colored diamonds, but is it really possible? The yellow color in fancy yellow diamonds are graded as follows:

Fancy Light Yellow
Fancy Yellow
Fancy Intense Yellow
Fancy Dark Yellow
Fancy Deep Yellow
Fancy Vivid Yellow
You may be wondering what the difference is between low-end Cape series diamonds and the Fancy Light Yellow (FLY).

Well low-end Cape series diamonds are actually classified in their own semi-official ranges of what is known as faint to light. Just like DEF is known as the colorless range, KLM is the faint yellow range, N to R is the very light yellow range, and S to Z is the light yellow range. But the ‘fancy’ designation in FCDs mean that the body color should be more evenly spread out through the diamond in comparison to a low color Cape series.

Fancy Color Diamonds
The most important thing a prosumer needs to know is that FCDs do not receive a cut grade like a colorless diamond. The reason is because fancy colored diamonds are graded and valued primarily by the intensity of their color from the face-up view. The good thing about FCDs is because although cutting them is more complicated than colorless rounds, for the consumer it is actually simpler; especially if you’re considering fancy yellow and above intensities. The only considerations for a consumer is whether they like the color, then ensuring the color is even and as stated on the certificate, and finally an understanding of how rare the particular stone is will help you understand its value. For example, natural green, green-blue, and pink diamonds are some of the rarest fancy colored diamonds and command the highest premium.

The colorless round brilliant cutting philosophies where perfect symmetry and polish are positives do not apply for fancy colored diamonds. The concepts of brilliance where optimising for brightness and contrast also do not necessarily apply. In fact, contrast in a FCD can be seen as a negative because it may be detrimental to the overall evenness of the body color. Reducing contrast is the first method of color retention in fancy color diamonds.

Just because a FCD might not have perfect symmetry and polish, this does not imply that FCDs are cut imprecisely; in fact quite the opposite is true. Cutting a FCD is much more of an art than cutting a colorless diamond. The reason is because sometimes the diamond may exhibit a certain overall intensity but are more intense in some parts of the diamond and less intense in other parts. The reason is because the impurities (nitrogen in the case of yellow diamonds) have not been introduced evenly as the diamond crystal was growing. This is known as color zoning, which also explains the faint to light range of diamonds in the Cape series.

Transforming Cape to Fancy Color Diamonds

Sometimes, low colored Cape series diamonds can make good candidates to be transformed into FLY diamonds given the right cut. It is highly debatable whether transforming these lower value diamonds into highly sought after fancy diamonds is ethical, especially as it can be seen to be masking the fact that these diamonds are not ‘true’ fancy color diamonds. Should a diamond which has been made into a FLY from a low colored Cape be as valuable as a ‘true’ FLY? This is a question best answered by the market. That, however, assumes that consumers can make an informed decision after given all the facts. Whether transforming a diamond into a FLY or improving the appearance of a FCD by making the diamond color even throughout the diamond, the cutter has to employ color retention techniques.

Another method to retain color in a diamond is to cut the diamond in a way that the light entering the diamond bounces around more times before leaving the diamond. As a general concept, the more times light bounces (undergoes total internal reflection), the more color is retained in the diamond. This is known as color entrapment.

This is the reason why certain shapes are more favourable for color and why most fancy color diamonds are cut to fancy shapes rather than a round brilliant, which happens to have the best performance in terms of brilliance but is actually the worst shape for color retention. The way fancy shaped diamonds accomplish more internal reflections is because of the extra crown facets and extra pavilion facets that some have over the round brilliant.

How Color Retention Affects Cape Series Diamonds

In order to think how color retention can affect Cape series diamonds, we can draw on some of the concepts we already know about brilliance and turn them upside down. For example, we know that relatively shallower pavilions increase contrast and it turns out that steeper pavilions help color retention. This would also suggest that crown-only painting of the girdles and shorter star lengths, which decrease contrast in a diamond, will have the same effect. The point to remember is that if you want your diamond to appear whiter, then that is more of a reason to optimise for brilliance.

In Cape series diamonds, color entrapment is a negative because if you are looking at J color diamonds, you probably want it to face-up whiter to ensure it stays in the near-colorless range rather than falling into the faint color range. You should be aware that a steeper pavilion angle will lead to increased color that is visible from the face-up view meaning that J will look more yellow.

It has been suggested that you will begin to see the effects of color entrapment with pavilion angles over 41 degrees. Color entrapment begins to be an issue for diamonds with tight tolerances at a pavilion angle of 41.4 degrees, with the effects becoming more obvious when the pavilion angle is 41.6 degrees and over. The reason is because the light entering the diamond through the girdle is likely to reflect internally many times off of opposing crowns and pavilion facets. Logically, the problems are worsened when more light enters the diamond through a thicker girdle. Face up, it has been suggested that the color will be most likely seen around leakage areas (ie. in the upper girdles and under the table). Also, for fancy shaped Cape series diamonds, the effect of color entrapment is also more evident than in rounds as the previous discussion would suggest. For example, in a princess cut, the corners of the diamond is more likely to experience color entrapment issues.

Please note that a lot of this depends on the color distribution in the particular diamond in the first place. Remember that diamonds that look differently can receive the same color grade because color is graded on color depth, which is a combination of tone and saturation. At the end of the day, all this does for us prosumers is that it raises additional concerns when picking diamonds in the hopes that they will appear whiter than their stated grade. You can only verify the existence or non-existence of the effect of color entrapment upon a visual inspection, and even then only if you have comparison stones available and have a pair of color sensitive eyes.

Maximising the Value of Your Diamond

Welcome to Prosumer Level 3! Congratulations, I already consider you a diamond prosumer. My aim in this tutorial is to discuss how to find out what is the best value when purchasing diamonds. You should know by now that this is highly influenced by personal preference. But what I have found is that many people honestly don’t have a personal preference or prefer a balanced diamond. Whichever type of diamond character you end up choosing, you ought to want to get the best value for your money. That means getting the most effect for what you’re going for, whether for size, light return, fire, or scintillation, or if you’re looking for a balance, still getting the biggest diamond that is possible for your given budget. I also want to remind you of the importance of tight variances that can only be guaranteed with precision diamond cutting. An H&A diamond is only one possible result of a precision cut diamond.

In my how to pick a diamond tutorial, I recommended that you refer to reference sizes for a diamond. But that only really works well if you’re looking for 0.25, 0.5, 1, 1.5, 2 cts, etc. It is less useful if you’re looking at a 1.17 ct diamond. Those charts also make assumptions about the depth and girdle thickness of the diamond. At this stage, I want you to forget those charts; we will probably rarely ever use them again.

Optimising a balanced diamond

Optimising a balanced diamond is the simplest, because it covers the most general points that you will want to consider when you optimise for any other type of diamond. The first thing you want to look at is the girdle thickness. The reason we want thin, thin-to-medium, or medium girdles is because these are relatively thin girdles without it being too thin and therefore prone to chipping. The difference between a thin and a medium girdle is around 1% girdle thickness. A medium girdle will look like a thin line and a thin girdle will just look like an edge. I think preference can dictate whether you want a thin or medium girdle, but lets just say that a good balance is therefore a thin-to-medium girdle.

Because the girdle is the widest part of the diamond, a 1% increase in the thickness leaders to a more than 1% increase in its weight. However, it does not increase the diameter of the diamond at all. So a thicker girdle is always bad for spread. Factor this into the cost of the diamond. In my opinion, the weight going into the girdle is less valuable so a 1.04 ct diamond with a slightly-thick girdle should not be that much expensive than a 1.00 ct diamond with a thin-to-medium girdle.

The next thing is the pavilion angle. Again, preferences aside, is there any reason why we would ever want a pavilion angle over 41 degrees? The only reason an end-user would ever want a 41 degree pavilion angle is that it compensates for shallow crown angles. But we know that 41-degree pavilion angle is at risk of leakage. The reason why a cutter will want to cut as steep a pavilion angle as possible without leakage is that this maximises their rough yield. But you have to think that as an end-user, what is good for the cutter may not necessarily be good for you. We also know that a 40.4 degree pavilion angle will have obstruction problems. Therefore the shallowest pavilion angle on the certificate is 40.6 degrees and you want to ensure that the actual pavilion angle is over 40.5 degrees. If you’re risk adverse then it is probably safer to get a 40.8-degree pavilion angle on the certificate.

With the general stuff out of the way, lets put everything we’ve learned so far together and talk about how to optimise each of the types of diamond that I mentioned at the beginning of the article.

Optimising for Size

Optimising for size is fun! It involves thinking about what are the reasonable hits we can take on other aspects in order to increase the diameter of the diamond. We’ve already talked about the girdle and the pavilion. Applying what we have talked about we are looking at a thin-to-medium girdle with a tight 40.5 degree pavilion angle. Can you guess why you wouldn’t want a thin girdle here?

Another way we can increase spread is to look for the lowest crown height possible. However, there is no such thing as a single ‘lowest crown height’ per say, because this varies with the size of the diamond. Rather, we want to find the smallest table coupled with shallowest crown angle to produce the lowest crown height possible for any particular diamond. I’ve said before its hard to find modern round brilliants with very small tables but lets think hypothetically.

I will begin with a 50% table, which is the smallest I think you’re going to be able to find. We are outside the range of GIA excellent cuts here, which will also save you some money. The shallowest crown angle that will stay within a very good cut grade when coupled with a 40.5-degree pavilion angle is a 31.5-degree crown angle. Because we have shallow crowns and pavilions, you may want to consider longer lower girdles (80%) so that they don’t leak before the pavilions. With longer lower girdles and a shallow pavilion, it would mean that the stars will have to be shorter, but not too short that there will likely be painting of the girdles, which add unnecessary weight. That means you should aim for 50% stars. If you haven’t figured it out yet, the reason you don’t want a thin girdle is because you also have quite shallow crowns so it may be more prone to chipping.

Lets sum it all up now:

The specs would be:

Thin to medium girdle
50% table
31.5 degree crown angle
40.5 degree pavilion angle
80% lower girdles
50% stars
40-43 degree upper girdles
No painting or digging!
Optimising for Brilliance

Optimising for brilliance is a tricky thing because we know that brilliance contains the subjective component of contrast patterns. But regardless of the personal preferences as to contrast, there is a basic requirement of optimising brilliance, which is to minimise unwanted light leakage. The factors that affect personal preference the most is whether you want more or less contrast in the upper girdles. This will determine whether you prefer any crown-only painting. Whether there is painting will also determine the star facet length.

As for the rest of the facets, there are several ways to go about it. First you can consider a large table to let a lot of light in, something around 60%. This should be coupled with a tight 41-degree pavilion angle that will increase the amount of tilt required before you see a fish-eye and to some extent manage the size of the table reflection. We are actually trying to reduce dispersion by making the crown facets smaller so aim for a lower crown height. But we don’t want to go quite as low as optimising for size so I would recommend pairing with a 32-degree crown angle to remain within GIA excellent cut grade.

If you go for a painted girdle, it will make the diamond brighter around the edges. But if you do this, the diamond will be noticeably darker in the bottom half of the diamond when you look at it from the face-up view. A painted girdle is usually accompanied by shorter stars, and this will mean less obstruction and an overall brighter diamond albeit with less contrast. You will then be free to choose between 75% or 80% lower girdles. For my personal tastes, I wouldn’t go with too long of a lower girdle because I personally don’t think thin arrows look good with a large table/table reflection. Try not to get too long of star facets, I would stick to around 50% and it also plays well to go with shorter lower girdles (around 75%) to avoid too much head shadow/body obstruction.

Therefore the specs for a brilliance optimised diamond without painting is:

Thin-to-medium girdle
60% table
32 degree crown angle
41 degree pavilion angle
75% lower girdles
50% stars
40-43 degree upper girdles
no painting
The specs for a brilliance optimised diamond with painting is:

Thin-to-medium girdle
60% table
32 degree crown angle
41 degree pavilion angle
75 – 80% lower girdles
45% stars
<40 degree upper girdles
crown-only painting
Optimising for Fire

A few notes before we optimise for fire. Just remember that a diamond’s fire is more affected by lighting than any other factor. Also, diamond simulants have more fire than diamond but they sometimes have too much fire so that it looks too ‘disco-ball’ like. Finally, if you really like fire, there is such thing as ‘fire polish’ that you can apply to the diamond to increase fire in a diamond. More on this in a later tutorial.

The first thing to do in optimising fire is to maximise the size of the crown facets. You do this by having a really high crown, and you get that by having a small table coupled with a steep crown. I would recommend a 53% table coupled with a 36-degree crown angle, which keeps you within GIA excellent cut. You want a slightly shallower pavilion (around 40.6 degrees) to compensate for the steeper crown angle.

Now we get into preference for either pin-fire flash or bolder flashes. If you prefer pin-fire flash and to maximise scintillation, then you will want at least 80% lower girdles and perhaps even closer to 85%. With such thin arrows, you may want more of them and that’s when I would refer you to the Solasfera cut. Be slightly careful with your choice for stars here. If you have very long lower girdles (85%) then you should probably stick to 50% stars. If you have closer to 80% lower girdles, then 55% stars will produce larger hotspots adding more pin-fire flash.

For a fire-optimised diamond, you don’t want any painting of the diamond as that reduces contrast. The leakage in the upper girdles from an unpainted diamond that you see in the face-up view will return flashes of light adding to scintillation when the diamond is rocked.

If instead you like bold flashes, you will want shorter lower girdles (75% or less). Even if you have decided on bold flashes, you can still make a decision about whether you want to only have bold flash or mix it in with some pin flash as well for a more balanced appearance. If you want a balance of pin and bold flash, you will want stars that are at least 55%. Just make sure the upper girdles are not so steep that they begin to leak when they are over 43-degrees. If you want to focus only on bold flash, you can stick to 50% stars and also consider painted girdles. This will reduce the prevalence of hotspots the contrast in the edges of the diamond so that your attention will be focused on the larger events of flashes coming from the arrows.

To summarise, the specs for a pin-fire flash/scintillation optimised diamond are:

Thin-to-medium girdle
53% table
36 degree crown angle
40.6 degree pavilion angle
80% lower girdles with 55% stars; or
85% lower girdles with 50% stars
40-43 degree upper girdles
no painting
The specs for a balanced-fire flash optimised diamond are:

Thin-to-medium girdle
53% table
36 degree crown angle
40.6 degree pavilion angle
<75% lower girdles
55% stars
40-43 degree upper girdles
no painting
The specs for an bold-fire flash only optimised diamond are:

Thin-to-medium girdle
53% table
36 degree crown angle
40.6 degree pavilion angle
<75% lower girdles
50% stars
<40 degree upper girdles
crown-only painting
Optimising a Balanced Diamond

To complete this tutorial, these are the full specs for what I consider to be an overall balanced diamond. The balanced diamond achieves a nice balance between spread, brightness, contrast, pin and bold fire flash, and scintillation.

Thin-to-medium girdle
57% table
34.5 degree crown angle
40.8 degree pavilion angle
75% lower girdles
55% stars
40-43 degree upper girdles
no painting

Pricescope Rockytalky Review: Aprilbaby

It’s time for another Pricescope Rockytalky review!

I noticed yet another recent thread that had an interesting question about Whiteflash ACAs. The specific question was whether all ACAs are made exactly the same and would PSers ever recommend against one? The question was raised because of concerns that the ASETs and Idealscope of some ACAs, in particular those under half a carat, varied a bit and that some idealscope also showed what appears to be leakage.

You can read the original thread here.

The short answer would be no they are not all made exactly the same and Whiteflash does not claim that they are. The simple reason being that there are always going to be borderline cases, and you would also expect the rare but unavoidable human error. The general answer is that yes, if you purchase a Whiteflash ACA, it is very highly likely that you will be a satisfied customer. The full answer, however, would require some knowledge of how a diamond is cut, which is going to be the topic of a future tutorial. For now, it is sufficient to know that diamonds cut to super-ideal standards are precision cut, and the cutter is usually able to cut the diamond very precisely. Also, if you’ve read all my tutorials, you will know precisely how each facet affects the appearance of diamond. Equipped with this knowledge, you too would expect there to always be an explanation for what you can see in any image of a diamond whether actual or light performance related.

In the thread, three ACAs in total were brought up for discussion. The first two were compared first:

Diamond 1
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2684406.htm

Diamond 2
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2982215.htm

The first question about these two diamonds was whether Diamond 1 had a better idealscope than Diamond 2. The person who posed the question thought that Diamond 2’s ASET was more dull and the idealscope was more grey and less vibrant. The more experienced PSers handled the question well noting that you should not be comparing the color saturation of different ASET images with each other.

However, no one seemed to look more carefully to see what else could explain the differences seen. Without even looking at the idealscope, you can see that Diamond 1 has more contrast around the edge of the diamond. This is because Diamond 2 has slightly painted girdles. This is of course verified by looking at the idealscope and what I believe is the proper answer to why the idealscope appeared more grey is actually because it has more deep reds in the upper girdles. It is often difficult for untrained eyes to distinguish dark-greys and deep reds in idealscope images. The ASET also tells the same story and you can see it manifesting as ever slightly increased green areas, lengthening in the upper girdles and thickening around the stars facets.

Does the existence of slight painting change what I think about ACAs? Certainly not, because it still exuberates a familiar characteristic contrast pattern under the table facets. You can think of slight painting as a sprinkle or topping to the diamond that you can choose whether to go with or without. Be minded that the reason slight painting is used here is most likely to ensure the diamond is over 1ct in weight.

The next comparison was between Diamond 2 and Diamond 3 below:

Diamond 3
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2949573.htm

Interestingly, Diamond 3 is a good example of why an ASET tells a clearer story than the idealscope. Untrained eyes are not likely to notice the widening of the leakage areas around the edges indicating steeper upper girdles in an idealscope image. The upper girdles are not so steep that they cause obvious leakage, but under the ASET, it is clear that at least 10 of the 16 upper girdles are steep enough to be returning light from the periphery (green on the ASET). A further inspection of this diamond’s proportions confirms that this is not what I am used to seeing in a typical ACA. Because of this, I had a quick peruse of some of the other ACAs under half a carat and I noticed that there is more variation in proportions in these smaller diamonds than there are for diamonds 1ct and above.

Now I can see how these diamonds still make it to the ACA level, after all, they are still well within my recommended proportions, with precision cut H&A, and near 100% light return. The subtlety here is that where the light return is coming from in the upper girdles is more from the periphery rather than from around a 45 degree angle, the latter in my opinion is preferable. This diamond does not have the best edge to edge light performance and is likely to pick up all sorts of color reflecting from its surroundings.

The conclusion of this review is that most ACAs are made the same, but there are some borderline cases, which I personally would avoid if I were purchasing an ACA. If you are looking for an ACA and have any doubts/questions. Please feel free to send me an email or leave a comment.

Crafted by Infinity Review

Crafted by Infinity is actually a brand sold exclusively by several dealers rather than a brand owned and sold by a single online vendor. There are some immediate advantages to this. The first that is evident to me is that the quality of the product will likely be higher because of the additional vetting process by the nature of having more parties involved. Second is that the cutting house is more focused on what they specialise in and don’t have other internal pressures to save costs by retaining carat weight on their diamonds. Third is that the brand must have some kind of unique look about them that can be immediately recognisable.

As I was browsing the Crafted by Infinity website doing this review, I came across an important point. Cut grading is in its infancy and unlike color or clarity, what is graded excellent today may not be excellent in a few years time and this can have serious implications on the future value of the diamond you purchase. Of course, you don’t have to purchase an Infinity diamond to protect yourself. There are also many reasons that precision cutting and H&A may never become a recognised superior cut grade by the major labs.

Crafted by Infinity makes an effort to market their diamonds as ‘superideal’ and that their diamonds are cut to perfection. They claim that their diamonds are cut to such rare standards that it is more rare than D color and IF clarity. They make a point to say that they cut ‘only’ 1000 diamonds per year. They say that their brand’s best feature is “Flawless Cut”. I have no problems with most of these claims as they are mostly true. For example, I have heard that superideal cut diamonds are in the top 1% of all diamonds cut and D-E color diamonds make up around 2% of diamonds. What I do have a slight problem with is the idea of a flawless cut. Although there is also no standard for what a flawless cut is, we do know that most H&A diamonds have minor defects. Diamonds that have several minor defects or major defects will not be considered H&A by some vendors. So I can tell how strict a H&A vendor is by how many defects they accept as part of their brand. A H&A vendor that markets their diamonds as ‘Flawless’ to me is potentially misleading consumers and together with the whole marketing pitch makes me feel like I am expecting top-notch quality even amongst the H&A vendors. We will find out later in this review whether the Infinity diamonds hold up against such high expectations.

Crafted by Infinity does not sell diamonds on their own website. However, on their homepage you will find a link to their dealers around the world. As I look through the list, the two vendors I have heard of already are High Performance Diamonds by Wink Jones and Diamonds by Lauren by David Friedlander. Basically, each online vendor will carry the same list of Infinity diamonds for the same price, using the same search engine. The search engine is pretty basic and you can only choose between round and princess cuts, the 4C’s, and price. Lets see if there really isn’t any need to have advanced search functions.

First there are only about 100 diamonds in total, I managed to find 6 G to H VS2 diamonds to compare. The information on Infinity’s system is not presented very well, with the table, depth, pavilion, and crown information only visible if you click on a button labelled ‘expert details’. Even then, there isn’t any information about the lower girdles length or girdle thickness information and you have to find that information on the AGS lab report yourself. As far as I can tell, all of the Infinity diamonds are graded by AGS, which has both its positives and negatives, as you will know from previous tutorials. One positive is that Infinity provides AGS lab reports that also have the hearts view so that provides an independent verification of the hearts image.

I collected the data from the 6 diamonds and put in them in the table below:

Infinity Table

All of these diamonds have thin to medium girdles, which helps the 1.01 ct stone to reach that 6.5mm mark that is expected of an ideal 1ct diamond. Apart from this, the only things I can comment on is that the table size is generally between 55% and 57% and each one has a total depth under 62%. From the small sample above, it does not seem like there is a specific pavilion angle that these diamonds are cut to like the Brian Gavin Diamonds stones. This is a positive for those who are about squeezing the last bit of carat weight into the diameter of the diamond. The theme of spread continues as I look at the crown facets. All of them are between 34 – 34.5 degrees and this means two things – better spread and a brighter stone under the table.

Finally I have a look at the lower girdle facets and all but 2 of them have a 78% lower girdle length with the other two 75% and 77%. Although probably not representative of all of their diamonds, I can only conclude that there is not a single contrast pattern of the arrows on all Infinity diamonds and you still have that freedom to choose your preference. It also seems like the lower girdle facets are cut so that they are just under 80% in order to achieve a hearts pattern that does not have a clear clef in the middle of the hearts.

So far all of the numbers look good right? Well we know that these numbers only tell half the story so lets get into the hearts image and idealscope images to see how the Crafted by Infinity diamonds hold up to their reputation.

Light Performance

Here are the 6 idealscope images.

table of idealscopes

From a light performance point of view, all of the diamonds above seem to look good in their idealscopes with no visible leakage. The light return also seems very balanced throughout the diamond. Although it may seem like there is no leakage in the upper girdles and that there may be some crown-only painting, it is not the case here as I think this is more to do with photography.

actual1    Eightstar
You can see from the actual image of the 1.03 GVS2 on the left that there is some contrast in the upper girdles. On the right is what an idealscope of a Eightstar diamond that has crown-only painting looks like. So you can see that the idealscope images of the Infinity diamonds are clearly not the same.

Optical Symmetry

table of hearts

The first diamond in the table is the 1.03 GVS2. Apart from some yaw and distorted V’s, which I consider minor, there is a defect here that some H&A vendors could find cause as to reject this diamond as a true H&A. Take a look at the heart at the 12 o’clock position, this heart is slightly smaller than most of the rest. You can see that the gap between the heart and the V is bigger than all the rest apart from the opposing heart. The idealscope tells the story more clearly the larger hotspot in between the second and third arrow is a clear indicator of a smaller heart. In the case of this diamond, the opposing heart is also slightly smaller. This helps the diamond visually but it still misses the mark as a true H&A in my books.

Surprisingly, the rest of the diamonds have some serious problems with yaw. The V’s are also mostly distorted and there is some serious misalignment of hearts as well as V’s. Although not a cut issue, I also noticed an inclusion that reflects around the pavilion in the third diamond, what is known as a ‘reflector’. This is not good for a VS2 diamond and you can definitely find better. There are actually all sorts of H&A defects in these examples. In the fifth diamond, the hearts are touching the V’s indicating shorter lower girdles. I’m pretty sure that this is the diamond with the 75% lower girdle length as stated on the certificate. The problem is that this heart image indicates lower girdles that are tending to the short end of the average stated. If you are not a H&A purist and like thicker arrows producing bolder flashes, then this 1.05 HVS2 may actually be one of the better choices out of this sample as the defects do not affect the face up view. The defects to the lower girdles go both ways as although the stated longest lower girdles were 78%, it is clear that some of these hearts, in particular the third diamond, display a clef in the middle that could also cause a rejection for some H&A vendors.

Price

The 1.03 HVS2 in this review costs $10,687. A quick comparison with James Allen, which I have found to have both great prices and quality that at least match what I have seen at Crafted By Infinity, shows a 1.01 HVS2 True Heart to cost $8,310. This is a 26% premium on a price per carat basis. This is before an up to 5% pricescope discount on James Allen, you get the idea…

Value Added Services

As Crafted by Infinity is not a retailer themselves, each of their dealers will have their own value added services so I will not go over them here. There is one interesting value add that Crafted by Infinity provides and that is their ‘Meet the Cutter’ events. This gives a chance for any Infinity owners to go to any one of their dealers who is holding one of these events where they get to meet the person who cuts their diamond. I guess this may appeal to some of you out there.

Conclusion

I have to say that I am a bit shocked to see some of these H&A defects on Crafted by Infinity diamonds. This is because I previously held their diamonds in high regard due to their great reputation and the price premium they command. Crafted by Infinity produces beautiful diamonds and that’s for sure. But I have found them not to hold up to their claims that their diamonds are cut flawlessly, at least to my standards here, which are influenced by the general quality that I see amongst the online vendors that anyone in the world has easy access to. A positive for Infinity diamonds is that I have found that they are cut for spread and you will get a good sized diamond for the stated carat weight. This also means that their diamonds tend toward the brighter side of my recommended range of proportions rather than the dispersive side. Their excellent spread is due to their attention given to the thin to medium girdles, close to 56% table percentage, 40.7-degree pavilion angles, and close to 34-degree crown angles. All things considered, I actually wouldn’t recommend Crafted by Infinity to my readers as I do believe that there are better and cheaper alternatives out there.

Diamond Crown Angle

Today I’m going to be discussing the importance of the crown facets, the fifth tutorial in the level 2 series. More specifically I will be explaining how the crown facets affect light performance. What this tutorial will try to establish is that maximum light return is not the primary thing that we are looking for, but rather we want to find a combination of crown and pavilion facets that work together in a way that unwanted light leakage is avoided and dispersion and fire are optimised.

Now before I continue, I want to mention that any analysis on a diamond is tremendously dependent on the light sources, anything that is considered ‘ideal’ only holds true if you view the diamond in the same conditions that it was assessed and analysed in. So because in reality it is rare that you will observe a diamond in the same conditions, if you’re looking for a diamond that performs well in real life, then much of this information will not be important to you.

These conditions are usually a light source at a particular light temperature and at a particular angle to the diamond. The main point to remember is that diamonds are assessed faced up so we are mainly concerned with what affects face up appearance. The reality is that it is impossible to optimise a diamond for every single viewpoint and that is why it is easier and more practical to focus on the face up view.
 
Light Performance

Without going into detailed analysis on diamond design, the basic concept as I understand it is that the pavilion of the diamond is designed to act as a mirror to bounce light so that light entering the top of the diamond also leaves through the top. The general idea is that if the crown angle is steeper, then the pavilion has to be shallower to compensate and vice versa.

This suggests that there is a single crown angle that maximises the light return. It also suggests that as you deviate from the ideal, there will be a point where the light return becomes detrimental to the diamond. Hopefully, none of this is new to you so far. After all, the grading labs are of course aware of this and penalise diamonds where they deem the proportions are detrimental to the appearance of the diamond. Since most of us will only be focusing on diamonds that achieve GIA ex/AGS0, what we are trying to do here is to see if there is any point in being a bit stricter than the grading labs.

The main point that needs to be hammered through is there are many possible combinations of crown and pavilion angles that produce what may be deemed optimal light return. However, in my previous tutorial, I explored how the pavilion affects the appearance of the diamond in a way that is independent of the crown. What I have found is that most people tend to prefer pavilion depths/angles around 42.5-43%/40.6-40.8 degrees. So based on this, we have a good starting point to narrow down and find out your preferences for crown angle.

I have previously recommended 34-35 degree crown angles. The first question would be; do we want a shallower crown angle within this range?

Well before I can answer this, I will say that having picked what are considered ‘ideal’ crown and pavilion angles to work with, we expect light return to be excellent with a shallower crown angle within this range. But varying the crown angles also changes how the diamond exhibits fire by changing its dispersion. Different materials disperse light differently but apart from being a material property, dispersion is affected by the angle of incidence of light rays that leave the diamond. So the answer to the question above is “not necessarily” because in general, the shallower the crown angle, the lower the dispersion is from the diamond.

It is also interesting to know that with very shallow crown angles, it has been suggested that there may be a potential durability issue when coupled with thin girdles. The reasoning is because more of the girdle is exposed increasing the probability of chipping. Personally, I understand how there is an increased risk, but compared to the general risk of chipping to any diamond with a thin girdle, I don’t think that a shallow crown angle changes that risk significantly for me to worry about.

So does this mean we want a steeper crown?

Well according to standard assessments, a steep crown angle will disperse light away from the observer in the assessment. But to other people who see your diamond in real life, it is likely that they may see more fire in your diamond with a very steep crown angle. However, with a very steep crown angle the diamond will not look very diamond shaped because we have also determined our preferences for table percentage independently. Remember, for a fixed table percentage, a shallower crown means a shorter crown height, and conversely a steeper crown would mean a higher crown. A higher crown means that a lot of the diamond’s weight goes into the crown height rather than the width and hence reduces its spread.

Also, for a fixed table percentage, a higher crown means that crown facets are larger and that means that more incident light rays can fall onto the prism-like crowns generating more dispersion. All this means that a crown tending towards the steep side will have more fire.

Does all this mean we want a steeper crown to maximise fire? Well, the answer is also “not necessarily”. All I can say is that from my observations, for the same pavilion angle, a steeper crown generally produces weaker light return under the table. This makes sense when you consider how a steeper pavilion tends towards leakage and how a shallower crown compensates this to some extent. Taken to the extreme, a very steep crown angle will begin to appear unacceptably dark. So now hopefully you can see why it is often aid that there is a trade off between brightness and fire.

What this also means is that if you have a steeper pavilion or one that is on the edge of leakage, a shallower crown may help improve its light return under the table, but this will be at a sacrifice of a little bit of dispersion. If we are talking about a 34.5/41 CA/PA combination vs a 34/41 CA/PA, my personal preference would be the 34.5/41. To me, the decreased light return is not such a negative effect that it warrants sacrificing the dispersion the diamond would otherwise have. If you have been following my tutorials, you will know that this is because weaker light return under the table can have a positive effect in terms of the contrast of the diamond. The only other positive for a shallower crown that I see is that it will have better spread as less weight goes into the crown height. As always, it is up to you to come to your own conclusions on your personal preferences.

With a 41-degree pavilion angle, I have assumed that the diamond has tight tolerances. However, if you are not looking for a H&A diamond and also do not have detailed measurements on the diamond, I would not recommend getting a diamond with a 41-degree pavilion angle as stated on the lab grading certificate. If you have picked a diamond with a 41-degree crown, I would say it would be safer to get a 34-degree crown angle with no other information available to you.
 
Physical Appearance

Before I finish, I will briefly mention how the crown angle affects the physical appearance of a diamond. To be honest, the crown angle has very little affect on the face up appearance. In general, a shallower crown will make the diamond a bit bigger for the same carat weight as it has better spread. In terms of the virtual facets, the shallower the crown angle, the closer the arrowhead is to the arrow shaft. On the other hand, for very steep crowns (>42 degrees), the arrowhead may begin to separate from the arrow shaft. Within the range of GIA ex/AGS0, there is not much affect of the crown angle from the face up view. Also, for very steep or very shallow crowns, the impact on the diamond’s profile view is probably a bigger concern.
 
Conclusion
 
In conclusion, very shallow and very steep crown angles, negatively affect a diamond either by negatively affecting its fire and brilliance respectively. Very shallow crown angles may also be prone to chipping. These negative effects will be taken into account in the diamond’s cut grade. The trade off between fire and brilliance makes a difference to the character of a diamond even within my recommended crown angles under close examination. A crown angle tending toward the shallow side can improve light return. A crown angle tending toward the steep side can maximise the dispersion from that diamond and create a different contrast pattern in the diamond. Finally, for stones graded excellent/ideal in cut, the crown facets have very little impact on a diamond’s physical character. However a shallow crown generally has better spread which may be an important consideration for some of you. If you are unsure of your preferences or do not have much information regarding the diamond you’re buying, then it may be safer choosing a 34.5 degree crown angle.