Most diamonds are found at 500Km below the Earth’s crust. Yet, currently the deepest
drill ever made on our planet reached only 13Km deep.
Despite some prehistoric volcanic eruption that carried these diamonds close to the surface, it appears that most diamonds will remain beyond our reach forever…
Fancy yellows are the most popular of all natural color diamonds. A diamonds yellow color is the result of nitrogen molecules absorbing blue light, making the diamond appear yellow (yellow is the complement of the color blue). A fancy yellow diamond sparked the first diamond rush in Africa in 1866. A fifteen year old shepherd boy found the 21.25 diamond dubbed The Eureka Diamond on the South bank of The Orange River near Hopetown. Another famous fancy yellow diamond created a different kind of buzz nearly a century later when Marilyn Monroe donned the 24.04ct diamond named The Moon of Baroda in her 1953 movie “Gentlemen Prefer Blondes”.
Until recently the cause of the pink color in a diamond remained somewhat of a scientific mystery. What is known is that unlike other fancy color diamonds (green, blue, yellow etc.) the pink color is not due to foreign trace elements trapped inside the diamond’s structure. Some scientists point to an atomic level lattice defect that selectively absorbs light producing a pink hue. Pink diamonds obtain their color from light reflected along growth planes. Disturbances during the growth process create graining planes (also called grain lines) that bend light and produce a pink hue.
In recent years two major events have significantly influenced the price of blue diamonds. The first being the fact that the principal mine producing the blue diamonds has passed its peak production capacity of blue diamonds. The second is that vivid blue diamond auction prices have been continuously breaking records. When Boron particles become trapped in a diamond crystal matrix, the result can be a stunning blue diamond. The percentage of these blue diamonds mined each year is negligible, with just a few stones recovered annually.
A fancy red is probably the most desired color in any fancy color collection. These gems are extremely rare and greatly desired, traits that have placed the color at the top of the value scale. Prices for these diamonds (when available) start at 7 figures per carat. The rarity of these diamonds also means that we have little gemological information about them. What is known is that crystal lattice defects showing stress lamination during the diamonds formation are the main cause of the red color. Every fancy color diamond, apart from the red, has the prefix “intense” or “vivid” in its color grading scale. Red diamonds, though, are never noted as being intense or vivid because gemological laboratories consider the red color itself as intense or vivid. The rarity of these gems is reflected in the price.
Violet diamonds have only recently been recognized as a separate color set. Yet some controversy remains over whether a violet can be marked as a separate category or whether it is in fact a member of the purple diamond family. Gemologically speaking, indicators currently point to the existence of two color sets based on the color’s source. The color violet in a diamond is due to the presence of hydrogen, whereas deformations in the diamonds atomic matrix result in a purple coloration.
Orange diamonds are somewhat of an anomaly. To be classified as an orange diamond there must be an absence of brown in the stone. As with red diamonds, the relative rarity of orange diamonds means a gap in gemological knowledge about the stones. What is known is that as the color orange is a mixture of the primary colors red and yellow, natural fancy orange diamonds range from brown-orange to yellow-orange, with most stones having a brown or brownish color appearance to naked eye.
The prices of green diamonds are somewhat parallel to those of pinks but greens are almost always grouped tighter together on the value scale. A green hue means that the diamond has spent a few million years being bombarded by radioactive materials (note that hydrogen may also be the cause in some yellowish green stones). The reason that a true green diamond is so valuable is that the radiation does not usually affect the entire gem, meaning that the stone may be green only in patches or on the surface; their beauty is only skin deep. And as with all beauty, if it does not come from within, it disappears under the slightest of changes. Most stones in the green family come from Brazil, Venezuela, and Zimbabwe. According to Stephen C. Hofer, author of Collecting and Classifying: Colored Diamonds, “Natural green diamonds are rare and old and are simply created by a set of unique geological factors.”
A chameleon diamond’s value is derived from its unique color-changing properties as opposed to the gem’s color intensity or saturation. The color scale for these diamonds is divided into two segments. The first segment consists of stones that feature a noticeable brown hue that some refer to as a “muddy” look. Stones in this grouping are usually poorer in clarity and luster. The second segment features an olive hue and show more brilliance and luster.
Brown diamonds that are light in color are sometimes referred to as champagne diamonds. Browns that contain a significant amount of orange mixed with dark brown hue are called cognacs. Plastic deformation (change in the diamonds molecule structure) is behind the brown color in diamonds. These stones generally contain lower levels of nitrogen (which causes the yellow coloring) than do other diamonds, making them more susceptible to these deformations.
Fancy grey diamonds are probably the most misunderstood color set of the fancy color diamond family. Referred to by many consumers as “silver diamonds”, the grey diamond with strong saturation can mimic a dark blue diamond (especially if viewed in sunlight). Few nitrogen impurities and scattered boron atoms in the crystal matrix cause grey diamonds to have their unique grey (and bluish) coloring.
Although black diamonds are somewhat more plentiful than other fancy color diamonds, the majority of black diamonds on the market have been treated to achieve their color. Black diamonds are primarily opaque in color, the color cause by crisscrossing fissures containing black deposits. Translucent or semi transparent black diamonds are rare. The worlds most famous black diamond, is the 67.5 carat cushion cut Black Orlov, is actually not black at all, but a very dark gun-metal color. As black diamonds exhibit no prismatic play whatsoever, their luster is incredible, featuring an almost metallic sheen.