Red diamonds are extremely rare. Basically they are very strongly and deeply colored pink diamonds, with the same cause of color, crystal distortion. This combination is so rare that most jeweler and diamond dealers have never even seen a natural red diamond. They do not get large with the 5.11 carat Moussiaf Red shield being the largest known red.
Gray diamonds are often steely in appearance and to an untrained eye may be hard to distinguish from colorless diamonds. When viewed side-by-side the difference is obvious, a gray diamond is darker than a colorless one. Pure gray diamonds are rare and are frequently described as a masculine color diamond.
Natural color white diamonds are not colorless, but are actually white. This can often cause confusion as the term is used loosely. A pure white diamond has a translucency or even opacity that makes the diamond white. This is often caused by sub-microscopic inclusions. They occasionally exhibit a weak play of color (similar to opals) called opalescence. These are highly prized among conniseurs.
Purple diamonds are very rare. It is believed that they have a similar cause of color as pink diamonds; crystal distortion. They are most often found in Siberia and are generally small in size. There are no historical or famous purple diamonds. This may be due to their inhospitable location. Purple diamonds larger than 5 carats are extremely rare, and their color rarely reaches the intense and vivid color grades.
Even though these stones are quite beautiful, Brown Diamonds were not at the top of the popularity charts. The Argyle mine, where many of the these treasures are found, began a brilliant marketing camping of changing the name to something far more attractive. The lighter brown shade has adopted the name of Cognac Diamonds for its rich and golden appearance. As a luxury drink, the mind easily connected the two and helped to increase the desire for such a stone. The darker or deeper brownish color, known as Champagne Diamonds, is really managing to attract the attention these stones deserve. As a desirable food that any man or woman can easily relate to, the term “Champagne diamonds” immediately began to attract attention.
Chameleon diamonds possess one of the most unique values in the fancy colored diamond family. As rare as all fancy colored diamonds are, these stones are so admired because of their magnificent color changing capabilities. They are the only natural diamonds that possess the ability to actually temporarily change color according to their environment.
There are two types of Chameleon colored diamonds.
Classic Chameleon colored diamonds possesses two very distinct natural capabilities. Thermochromic and photochromic behavior patterns. Its thermochromic behavior enables the stone to temporarily change to a darker color when heated from 150° Celsius to 250° Celsius, for a short period of time. As the stone cools off, its color gradually changes back to the lighter original color. Its photochromic behavior enables the stone to temporarily change to a darker color when stored in a dark place for a longer period of time. When the stone is exposed to light, the lighter color is gradually restored.
Reverse Chameleon colored diamonds, as the name suggests, act almost exactly opposite to Classic Chameleon stones. Reverse Chameleon colored stones have a darker stable color. Its photochromic behavior enables the stone to temporarily change to a lighter color when stored in a dark place for a longer period of time. When the stone is exposed to light, the darker color is gradually restored. Reverse Chameleon colored stones do not have any reaction to temperature changes.