Gray diamonds

When I discussed fancy brown diamonds in last week’s article, I stated that unlike other fancy color shades that are extremely rare in nature, brown diamonds are plentiful and therefore command much lower prices. However, there is another shade of fancy color diamonds that bucks this trend by commanding relatively low prices despite actually being quite rare. I am speaking about fancy gray diamonds, which have the potential to serve as an interesting purchase for investors and consumers alike. Fancy gray diamonds might even serve as an alternative to white diamonds, simply based on their attractive price.

Gray diamonds are mined principally in Brazil, Russia, South Africa, and Australia and account for less than 2% of all fancy color diamonds mined in the world. In recent years, more and more people have looked to learn about and understand these unusual gemstones. 

Unlike other fancy colors that often show obvious color saturation, gray diamonds tend to show a very subtle shade or tone. They often appear like white stones with a metallic or light bluish tint. For jewelry manufacturers, these stones can be used to produce very unique designs that give consumers the added benefit of exclusivity – sough by so many. 

Given their rarity and low cost, gray diamonds provide potential buyers with the opportunity to own a unique and personalized piece of jewelry without needing a large budget. Also, unlike most fancy color diamonds that are traditionally cut into fancy shapes like radiants, emeralds  and ovals  to maximize color saturation, gray diamonds look very nice when cut into round brilliants. This allows consumers to own a coveted round shape stone, while still owning a unique color diamond. Furthermore, gray diamonds have the added benefit of hiding inclusions inside the stone. Since natural inclusions are often dark or black, a gray diamond of lower quality may appear to show a slightly better clarity when viewed with the naked eye.

Prior to the development of more sophisticated diamond cutting technology around the 15th century and more modern cleaning methods, many diamonds were gray or black. There are several examples of pre-renaissance artists’ portrayals of diamonds that usually show a charcoal gray color.

Gray coloration is principally caused by the large presence of hydrogen. These hydrogen defects make the stone absorb equal quantities of light from all wavelengths. In some rare cases, gray can be caused by boron, a chemical that usually results in blue coloration. Scientists have not yet discovered why the presence of boron will cause some stones to turn blue, and others gray. 

Another benefit of gray diamonds is that they very rarely show any degree of fluorescence, and when fluorescence is present, it tends to be faint. Like blue diamonds, gray diamonds are semiconductors of electricity. This is highly unusual – a feature not shared by any of the other color or white diamonds. 

GIA has five color classifications for gray: light gray, fancy light gray, fancy gray, fancy dark gray, and fancy deep gray. There is no fancy intense or fancy vivid gray classifications. Gray diamonds often have secondary color modifiers including yellow, green, blue and violet. When a secondary blue or violet modifier is present, the price can jump dramatically, making these stones very expensive. Similarly, gray can be a secondary modifier to blue or violet, which tends to reduce the price significantly compared to a pure blue stone, for example.

In much the same way that fancy brown diamonds have been marketed with terms such as “champagne,” “cognac,” and “brandy,” gray diamonds have also been given color descriptions for better branding and marketing. Terms such as “steel,” “charcoal,” “slate” and “silver” have been used in a similar marketing effort with gray diamonds.

Since they are so rare as to barely exist in the world, there are no known pure gray diamonds of significant size that have achieved global renown. However, a few of the world’s most famous blue diamonds are actually gray blue. This includes the immortal Hope Diamond, the Wittelsbach Diamond – before it was recut by Lawrence Graff to be a pure blue – and the Sultan of Morocco Diamond.

Although these diamonds have historically been underappreciated, the world is waking up to the fact that gray diamonds are extremely rare and beautiful. Both as a sound financial investment and for use in jewelry, gray diamonds offer buyers a unique and desirable gemstone. 

The views expressed here are solely those of the author in his private capacity. No one should act upon any opinion or information in this website without consulting a professional qualified adviser.