Crushed Ice Diamonds

Diamonds come in many shapes and facet arrangements resulting in a tantalizing pallet of “flavors”. Antique diamonds and their modern reproductions feature fewer and larger facets creating slow, bold scintillation. Some proprietary facet designs feature an unusually large number of facets resulting in very fast scintillation but fewer bold flashes. Precision cut round brilliant diamonds have a mix of large, medium and small facets creating a dazzling display of brilliance and fire. And many fancy shapes produce a twinkling sort of light performance often referred to as “crushed ice”. The most common shapes featuring this appearance are the crushed ice cushion cut and the crushed ice radiant cut. To varying extents, other fancy shapes including ovals also feature crushed ice as part of their visual character.

Light performance is the result of cut craftsmanship and derives from a polished diamond’s virtual facet pattern. Virtual facets (VFs) are those reflections we see in a diamond in motion, which are far more numerous than the physical facets on the diamond. And they are the result of a complex interplay of facet design, proportions, length to width ratios, and specific facet angles. The image below illustrates a well-cut oval with its physical facet arrangement left, the virtual facets middle, and a rendering of the face-up virtual facet pattern on the right.

Even diamonds with the same facet design and similar proportions may produce very different VF patterns and have very different appearances. In crushed ice styles the VFs are very small and very numerous, so they generate a multitude of tiny sparkle events, and the scintillation is very rapid. The result is a distinctive “flavor” of light performance - crushed ice diamond sparkle creates a subtle twinkling appearance rather than a flashy or bold appearance that is characteristic of other cutting styles.

If you notice the cutting styles commonly used to craft fancy color diamonds, you will see a majority cut into cushions and radiants featuring crushed ice. These cutting styles create longer internal light ray paths thereby accentuating the degree to which they concentrate color to the face up view. Imagine a regular pane of glass with a very small amount of tint. The light passes through without becoming noticeably darker or colored. Now imagine a very thick piece of glass with the same amount of tint. The light passing through the thick piece looks a shade or two darker, simply because the light has passed through more of it- it has a longer path through the material before reaching the observer. This makes diamonds with long internal ray paths ideal for making fancy colored diamonds look richer and more saturated. But it also means that stones in the near colorless range might show some body color from the face up direction, suggesting it might be wise to target a color grade or two higher for these cuts.

When very attractive crushed ice style diamonds are mapped with ASET, a surprising thing is seen. The diamonds often return a large amount of low angle light (green), and show numerous points of light leakage scattered throughout. Those who are used to looking at ASET maps of round brilliants tend to see an ASET of a crushed ice diamond as relatively weak. But this flavor of light performance has a different ASET signature, and light performance images of crushed ice diamonds should only be compared against members of their own species. Below, the leakage pattern of this beautifully cut crushed ice cushion is best seen in IdealScope in the form of well distributed small light areas. It turns out that small areas of leakage can create contrast with illuminated facets contributing to scintillation - this is a phenomenon known as contrast leakage.

From the examples of full crushed ice cushions featured above, to hearts and arrows cushions, hybrid cushions, and antique style cushions, perhaps no other fancy shape has such a full spectrum of possible appearances.

Hearts and arrow cushions feature a brilliant style facet design generating a virtual facet pattern much more like a round. Antique style cushions feature fewer and larger physical facets, giving rise to bolder flashes of light and slower scintillation. Other modifications of the cushion cut facet design can result in various “hybrid” virtual facet patterns with crushed ice mixed with larger virtual facets. A fully crushed ice cushion cut is but one of many options in this versatile cut category.

Crushed Ice vs brilliant diamond styles involve a very subjective preference in terms of what we find most beautiful and alluring about a diamond. While an ideal cut round brilliant can often shoot impressive sparkles across a room, crushed ice styles are more subdued. They like to be admired from close range, and often seductively draw an observer into their little universe of tiny sparkles.

On the flip side is the idea that a diamond is a showpiece and its claim to fame is dazzling us with fire and brilliance. No diamond accomplishes this more than a precision cut, fully transparent round brilliant. And to the extent that other brilliant styles produce impressive visual displays, they find favor with the crowd that subscribes to the theory that “more is more”.

There is also a middle ground in which brilliant styles produce a variety of virtual facet sizes including areas of both crushed ice and larger virtual facets that give the stone more pop than a fully crushed ice style. These may require more careful evaluation however, as crushed ice areas of very small virtual facets that are contiguous with areas of very large facets can sometimes interrupt a consistent visual flow and give a diamond a disjointed look. This may in turn make issues like bowtie effect more prominent.

Crushed ice can also be a problem where virtual facets get too tiny. This can make them less distinct and crisp. This blurriness is sometimes described as “mush” by people analyzing patterns in crushed ice diamonds. A good balance of virtual facets in terms of size and distribution is the sign of a well cut stone with potential for nice light performance and visual appeal.

Crushed ice styles, owing to their myriad virtual facets, are also more sensitive to any transparency deficits in the material. This is true of both natural and lab grown diamonds. In natural diamonds it is not uncommon for inclusions to be the culprit in reducing transparency and making the stone look hazy. In lab grown diamonds, which are produced today in mostly very high clarities, the culprit is in atomic-level defects that are not captured in the clarity grade which is rendered at 10x magnification. Crystal stain, an inherent property of CVD grown diamonds, can sometimes cause transparency loss as can striation in the carbon lattice. Appreciable haziness will prevent any diamond from optimal light performance, but will be more detrimental to the subtle light play of crushed ice styles.

Crushed Ice is a style choice when it comes to diamond light performance. It is neither better nor worse than other styles - it’s just a different flavor of delicious. Why choose crushed ice diamonds?

• Sophisticated subtlety that beckons a closer look
• A vast universe of tiny sparkles
• A style that optimizes fancy color diamonds

• Does not produce as many large sparkles as other styles
• Requires closer viewing to fully appreciate
• Tends to concentrate body color to the face-up view

Other fancy shape diamonds such as ovals, marquises, and pear shapes can and usually do have areas of crushed ice. These areas of tiny virtual facets are usually in the tips or lobes. Relatively large virtual facets are found in the midsection of brilliant style fancies, and are commonly discussed in terms of the prominence of the bowtie effect. The virtual facet pattern is important in determining if the bowtie is distracting to the overall visual flow and eye appeal of the diamond. Only by evaluating the virtual facet pattern in motion through a full range of normal tilt angles can you determine factors such as persistence. If the bowtie is only visible or obvious through a small range of tilt angles, it is less likely to detract from overall eye-appeal. Whereas if it is visible through a large range of viewing angles it will be a more prominent feature of the diamond’s appearance.

Now you have some actionable information behind the crushed ice diamond meaning, which will help you select a high-performing gem of this style. The very small reflections (virtual facets) that characterize this flavor of light performance have a subtlety that draws the eye in, and is a style that is appreciated by many diamond lovers. It is a glittery diamond effect that is quite mesmerizing. There are some potential issues to be on the look out for including blurry virtual facets that can diminish sparkle or accentuate a bowtie effect or other factor causing discontinuity in the visual flow of the light performance.

Are crushed ice diamonds good? Beauty is in the eye of the beholder and there are many diamond aficionados who love them. It is important to understand your own taste when it comes to diamond beauty because people differ in their response to how diamonds perform. Some people like classical music and some like to rock!

Do crushed ice diamonds sparkle less? Absolutely not. A well cut crushed ice style diamond produces a tremendous number of tiny sparkles, far more than many other styles. But the sparkles are generally smaller. Therefore, the light performance is not as bold. You might say it is a soft sparkle versus a sharp sparkle.