Diamonds come in a variety of colors, from colorless to shades of yellow, brown, pink, blue, green and more. After colorless, the rarest diamond colors are red and green. Let’s take a closer look at diamond colors and rarity.
Diamond Color Scale
The Gemological Institute of America (GIA) grades diamond color on a scale from D to Z, with D being colorless and Z having noticeable color tint. Here is an overview of the GIA diamond color scale:
| Color Grade | Color Description |
| D | Colorless |
| E, F | Near colorless |
| G-J | Near colorless to slightly tinted white |
| K-M | Slightly tinted white |
| N-R | Tinted white |
| S-Z | Tinted color |
As you can see, most diamonds fall into the near colorless to slightly tinted color range. However, diamonds on the ends of the spectrum are much rarer.
Colorless Diamonds
Diamonds graded D-F are considered colorless to near colorless. These diamonds have little to no detectable yellow or brown tint. Colorless diamonds transmit light extremely well and have exceptional brilliance. They make up about 2% of all natural diamonds mined.
The most sought-after and expensive diamonds are those rated D colorless. A D color diamond is 100% colorless and has no trace of impurities that cause color. These diamonds are exceptionally rare, accounting for less than 0.1% of gem-quality diamonds. They command very high prices when cut properly into colorless stones weighing 1 carat or more.
Next in rarity are E and F color diamonds. An E color diamond will show a nearly undetectable amount of color, while an F may have a barely discernible warm tone but still faces up white. These make up around 1.5% and 0.5% of gem diamonds, respectively. Both are considered premium diamond colors.
Near Colorless Diamonds
Diamonds in the G-J range face up white with a possible pale yellow or brownish tint visible upon close inspection. The average engagement ring diamond is an H color. These diamonds offer excellent value, as the slight tint is barely detectable to the naked eye but makes them more affordable than higher colors. About 15% of diamonds fall into the near colorless range.
Fancy Colored Diamonds
Diamonds that exhibit noticeable color fall into the fancy color category. These diamonds get their color from chemical impurities present during formation in the earth’s crust. The rarest and most desirable shades are vivid and intense.
Red Diamonds
Red diamonds are the rarest diamond color. They account for less than 1% of all colored diamonds. Their scarcity makes them extremely valuable, typically more expensive than comparably-sized colorless diamonds. Pure red diamonds with intense saturation are the most prized. These fiery gems get their ruby red color from the presence of the crystal lattice defect nitrogen during formation. Large polished red diamonds over 5 carats are exceptionally unusual. Most red diamonds weigh under 1 carat.
Green Diamonds
Natural green diamonds are the second rarest diamond color after red. They comprise just 0.1% of mined diamonds. Green diamonds range from pale olive to vivid emerald green. Stones with medium to deep greens are the most sought-after. These colors are produced when diamonds are exposed to natural radiation in the earth. Green diamonds typically contain trace amounts of radiation, which is harmless. However, it does make them unsuitable for resisting. Well-saturated green diamonds over 1 carat are extremely scarce and valuable.
Other Colored Diamonds
After red and green, other natural fancy colored diamonds in descending order of rarity include:
– Blue – These range from steely grayish-blue to vivid blue. The coloring agent is boron.
– Pink – From pastel blush pink to hot fuchsia depending on the intensity of the structural defects that cause the color.
– Yellow/Brown – Canary yellow to champagne colored. Nitrogen impurities cause the color.
– Purple/Violet – These extremely rare diamonds get their color from hydrogen present during crystal growth.
– Orange – Vivid orange diamonds are highly sought after for their fiery brilliance. They occur when nitrogen and hydrogen are present.
– Black – True black diamonds are incredibly scarce. Most “black” diamonds are actually very dark brown or grey.
Conclusion
When evaluating diamond rarity, colorless diamonds graded D-F make up less than 2% of gem diamonds, making them much scarcer than near-colorless stones. Of the colored diamonds, red diamonds are by far the rarest at less than 1% of the total colored diamond population. Coming in second is green diamonds at 0.1% occurrence.
While the rarest diamond colors tend to be the most expensive, even pale shades can be prized in large carat weights. Exceptional saturation and tones also impact value for fancy color diamonds. But in general, D colorless and rich red diamonds are the pinnacle of diamond rarity and will have the highest prices per carat. Beyond investment value, these rare diamond colors offer stunning brilliance and beauty.