Color refers to the actual body color (the color of the material itself) of the diamond. This is different from the play of color (the flashes of rainbow colors) that results from dispersion. Diamonds will range from colorless (D on the scale) to yellow to brown (Z on the scale), with only very slight tinges of color separating each grade in between. Without a set a guide stones for comparison, it is very difficult to discern color differences or to see color in a mounted stone through I color. Most diamonds are shades of white to yellow to brown, however, there is a rare classification of diamonds called fancies that come in a wide variety of colors.
While diamonds are 99.95% simple carbon in composition, the presence of certain trace elements will create color in a diamond. The presence of nitrogen will create yellow in a diamond. Boron causes a diamond to be blue. The Hope Diamond is the number one most visited exhibit in the Smithsonian. Its mysterious legend and rich blue color make this 45.52 cushion cut diamond an object that people have admired for many years. The rarest of the fancy diamonds is red of which only 10 are known to exist in the world. Blue is the next most rare. Pink is also very rare and the recent highly publicized celebrity engagements with pink diamonds have created more awareness and desire for pink stones.
The best way to think of colorless is to imagine a drop of pure, distilled water; of course, true colorless diamonds are very rare, and therefore, very expensive. D color represents 1% of all diamonds. D-E-F color is considered colorless, G-H-I near colorless, J-K-L slightly tinted. Diamond is the only gemstone where “no color” is the preferred color. Virtually every other gemstone is valued for intensity and saturation of color.
GIA is the most widely accepted system; it is also the most stringent, with a smaller classification at the upper end. View a diamond through the pavilion to see body color (how much yellow or brown).
Differences between D-H in a mounted stone are very difficult to discern.
D Absolutely colorless. The highest color grade, which is extremely rare.
E Colorless. Only minute traces of color can be detected by an expert gemologist. A rare diamond.
F Colorless. Slight color detected by an expert gemologit, but still considered a “colorless” grade. A high quality diamond.
G-H Near olorless. Color noticeable when compared to diamonds of better grades, but these grades offer excellent value.
I-J Near colorless. Color slightly detectable. An excellent value.
K-M Faint yellow.
N-Z Very light to light yellow
A physical property that a diamond may or may not possess. Causes a diamond to appear a different color than it actually is when viewed in certain lights. Actually is a radioactive property.
It can produce a yellowish, bluish, or whitish glow in Sun-light or fluorescent light. Blue is the most common, and it can mask yellow; viewed in incandescent light (normal candle or regular lamp), the diamond will appear yellow, if indeed it is.
Doesn’t add or take away from value. Actually, it makes a diamond look bluish, which enhances color.
Diamonds that exhibit strong yellow florescence, however, will be lower in price, since it detracts from the beauty of the stone.
What Color Grade Is the Best?
For the purist, look for a colorless diamond with a grade of D-F and a fluorescence rating of faint, inert, none, or negligible.
For an excellent value in a diamond with no noticeable color to the unaided eye, look for a near-colorless grade of G-I, and a fluorescence grade of medium or strong blue.
Or, if you'd rather not compromise on color but would like to stay on budget, choose a diamond with a good cut, SI1–SI2 clarity, and consider going with a strong fluorescence. It will still be beautiful to the unaided eye and you may prefer the unique effect of a strong fluorescence.
Natural Fancy Colors
Red, pink and blue are extremely rare. Fancy color diamonds are valued for hue, tone, saturation, and intensity. The grading ranges from fancy, fancy light, to vivid. The least valuable but still expensive is black. On 4/28/87, Christies sold a 0.95 purplish red stone with 2 large flaws for $800,000. There are 10 known reds in the world!
Color is artificially enhanced through bombardment in a cyclotron field. Irradiated diamonds are much less expensive. Tests can be done to determine if color was enhanced artificially.