Colored diamonds are found in nature in copious amounts. According to the Gemological Institute of America, only one in 10,000 natural diamonds is a colored diamond. Although these diamonds can be found in any shade, there are 27 different hues for natural colored diamonds. The range of shades available naturally has led to thematic names and pairing with fashion trends.
Natural colored diamonds are all created in a similar fashion, with a miniscule difference that gives a unique color. When foreign particles get trapped during crystallization they alter the chemical process and change the eventual outcome. The result of this are beautiful and rare colors from exceptional diamonds.
Defects in a diamond crystal modifies the way that light can pass through. The diamond crystal then selectively transmits some wavelengths of light and opts to absorb some other wavelengths of light. Since each wavelength of light corresponds to a distinct color, this selective process determines the diamond’s color.
Diamonds owe their color to a combination of pressure and heat from the earth. Both of these cause distortions in the crystal lattice that absorbs light, to reflect a different hue of color. These are the structural defects that give brown diamonds their color. The now infamous Chocolate Diamond® starts with a brown hue. It is sometimes called “champagne diamond” (which is a lightly tinted brown diamond) and also “cognac diamond” (which is a darker brown diamond). These loose brown diamonds can be found in Australia, Africa, and Siberia.
Since brown is the most common color of colored diamonds they are present in huge amounts. They are abundant in many mines, most popularly the Argyle mine in Australia. Over 80% of the gem-quality diamonds produced in these mines are brown in color. The brown color can also be due to irradiation or nickel impurity but the majority of these diamonds do not show any kind of characteristic absorption. The color mostly relates to plastic deformation and large clusters of vacancies.
Despite the fact that brown diamonds are some of the most ordinary color diamonds mined, they are also quite special. They have the lowest of all the fancy colors, even the high quality ones. These eventually can be molded into Chocolate Diamonds®. There is a pushing marketing drive from big retailers that has led to their popularity. They are now used in a variety of jewelry designs all over the world.
The Different Hues of Brown
The main cause of color in brown diamonds is attributed to inner graining. Due to structural non-uniformity in a diamond’s crystal lattice there can be secondary colors present. The types of brown diamonds include yellow-brown, orange-brown and even pink-brown. Brown diamonds are still regarded as “fancy” because the stone presents more colors than the “Z” color grade within the D-Z color grading scale.
Brown diamonds of good quality used to be scarce before the Argyle mine. In the 1980’s most brown diamonds were mined previously for industrial use. Upon the discovery of “champagne diamonds”, “cognac diamonds”, and now Chocolate Diamonds®, these are now famous jewels employed in accessorizing. The latest and most popular term used to market rare brown diamonds is ‘Chocolate Diamond®’.