Pink, blue, green, red or other naturally colorful diamonds are Fancy Color or Colored diamonds. They are very rare creations of nature and the majority of them - more than 85% of the fancy color polished diamonds - are fancy yellow diamonds smaller than 1 carat.
Fancy color polished diamonds weighing more than 10 carats are extremely rare. With the exception of large fancy yellows, only one or two 10+ carat diamonds are found annually. Orange color diamonds weighing more than 10 carats are so rare that the rough yielding them is found only once every few years.
The reason for this extraordinary rareness is that the conditions to create diamonds of any kind in nature are exceptional, requiring extreme heat and pressure over extended periods of hundreds or thousands of years, and the presence of carbon. Fancy color diamonds are a twist in creating diamonds, requiring the introduction of various elements to the mix, which are an even rarer occurrence.
This great scarcity, and the beauty of fancy color diamonds, makes these diamonds very special and unique, and their value extremely high.
Causes of Color in Diamonds
There are two main causes of color in diamonds: impurities and structural damage. The impurities are the presence of nitrogen (N) or boron (B) inside a diamond. The structural damage is mainly crystal lattice defects.
The yellow in diamonds is the result of the presence of nitrogen caught in the diamond during its formation. A small trace of nitrogen, one part in a million, will result in a yellow tint that will result in a K color diamond. A little more nitrogen will result in a fancy color yellow diamond. The nitrogen atoms filter the blue-violet range of the visible light spectrum. In some diamonds, the presence of nitrogen may result in a pronounced yellow hue, such as a canary yellow.
Pink, according to scientists, is apparently the result of enormous pressure leading to structural damage to the diamond and the displacement of carbon atoms. Blue diamonds are usually the result of the presence of boron. Another less common cause is high levels of Hydrogen that block the deep red and some of the yellow-green range of the visible light spectrum.
Natural radiation creates Green diamonds, likely from resting hundreds of thousands or millions of years near radioactive material such as Uranium. Red is the result of the same structural damage that causes pinks. According to Japanese scientist Hiroshi Kitawaki, pink diamonds with moderate brightness and high saturation are identified as red diamonds.
Grading Fancy Color Diamonds
Fancy color diamonds are all about color, and are therefore evaluated on color intensity, as opposed to colorless and near-colorless diamonds. When grading the color of a fancy color diamond, a diamond's hue, tone and saturation are considered.
Hue is the color of the diamond and it is expressed as a noun, such as yellow or pink. If a diamond has a secondary color, it is stated before the primary hue and is expressed as an adjective, such as brownish-yellow of purplish-pink. If a grader decides that a diamond has two hues with even or near-even presence, they are stated as nouns.
There are 27 diamond hues, listed below in alphabetical order:
Once a diamond's hue is determined, the hue's tone – its relative lightness or darkness – is decided. The Gemological Institute of America (GIA) uses a seven-step scale to describe tone:
Finally, saturation, the color's intensity, is measured and graded on a nine-step scale:
The combination of hue, tone and saturation results in the color grade, Fancy Vivid Yellow-Orange, for example.
In addition to color grade, fancy color diamonds have another important attribute - distribution. If color spreads evenly across the diamond, it is graded even. Otherwise, it is graded not even.
Fancies and Value
As part of the Crystal Clear philosophy, we described in past articles how different characteristics impact a diamond's value. With all else being equal we saw that heavier diamonds have a higher value than smaller ones, a diamond with better clarity has a higher value and a diamond with a better cut has a higher value. In the article on white diamonds we saw that diamonds with less color are higher value, but with fancy color diamonds, value rises the deeper and stronger the color is.
As the following graph shows, based on an analysis of market prices of pink and yellow 2-carat radiant shape VVS diamonds, the value of fancy color diamonds jumps sharply as color becomes more pronounced.
Performing the same analysis of pink and yellow 4 carats SI1 radiant shape diamonds shows a similar trend - value jumps significantly and for the deepest color, Fancy Vivid, the value soars can more than double compared to Fancy Intense.
Another conclusion that we can derive from the above graphs is that the value of pink diamonds rises more rapidly than those of yellow diamonds. However, what happens when we compare diamonds that are identical by all characteristics except shape? Let us compare the value of a 3 carat, VVS2 with a Fancy Intense Yellow color.
As stated in past articles, the intention of this review is to highlight a number of issues relating to diamonds, their value and how to understand the differing values of diamonds that may seem identical, but differ enough to impact their value. These concepts are important to keep in mind if considering diamonds as part of a wealth preservation belief or even as a gift.
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