The word “diamond” comes from the Greek word “Adamas” and means “unconquerable and indestructible.” Most natural diamonds are formed at high temperatures and pressure at depths of 140 to 190 kilometers in the Earth’s mantle. Approximately 130 million carats of diamonds are mined annually with roughly 49 percent originating from Central and Southern Africa. Diamonds aren’t typically mined in the U.S., but they have been found in Arkansas, Colorado, Wyoming, and Montana.
Besides the commercial market of clear diamonds, the popularity of fancy colored diamonds has been on the rise. This is especially true in the antiques industry where natural yellow diamonds were once quite popular.
Colored diamonds are either found in nature or created in laboratory settings. Large, vivid fancy colored diamonds are extremely rare and very valuable. Approximately one in every 10,000 diamonds has a fancy color and the Gemological Institute of America (GIA) lists 27 different hues for natural colored diamonds. The most valuable hues are pink, blue, green, and red, which are so unique that only a handful are known to exist worldwide. “To say a red diamond is one in a million is certainly no stretch,” stated John King, GIA Laboratory’s chief quality officer.
There have been many notable colored diamonds throughout our history. The most famous is the Hope Diamond, which has a long and coveted history and may be world’s largest blue. Several accounts suggest that the diamond originated in India in the 17th century when the French merchant traveler, Jean Baptiste Tavernier, was said to purchase it. This diamond, which was most likely from the Kollur mine in Golconda, India, was slightly triangular in shape and crudely cut. Tavernier sold the diamond to King Louis XIV of France in 1668. Five years later, the stone was recut by the court jeweler, resulting in a 67 1/8-carat stone and was set in gold and suspended on a neck ribbon which the king wore on ceremonial occasions. The diamond was owned by a variety of individuals throughout its lifetime including royalty and recognized jewelers such as Cartier. It is now housed in the National Gem and Mineral collection at the National Museum of Natural History in Washington, D.C.
In 1995, the GIA expanded its system to measure hue, tone, saturation and distribution of color in colored diamonds. “Hue” describes the color and can include a modifier such as purplish-pink. “Tone” refers to the stone’s lightness or darkness, and “saturation” implies strength or purity of color. The scale begins with “faint” and moves up to “light,” “fancy light,” “fancy,” “fancy intense,” and “fancy vivid,” the last being the most valuable.