Diamonds come in a variety of colors, ranging from colorless to shades of yellow, brown, gray, blue, green, pink, purple, orange, red and black. The color of a diamond is determined by the presence of certain chemical impurities or structural defects in the diamond crystal. Here are some key things to know about diamond colors:
Colorless Diamonds
The most common and popular diamond color is colorless. These diamonds transmit light without any color saturation, resulting in a sparkling white appearance. Colorless diamonds are the most chemically pure, containing little to no nitrogen impurities or structural defects.
Colorless diamonds are graded on a scale established by the Gemological Institute of America (GIA) as follows:
| GIA Color Grade | Description |
|---|---|
| D | Absolutely colorless |
| E | Colorless |
| F | Colorless |
| G | Near colorless |
| H | Near colorless |
| I | Near colorless |
| J | Near colorless |
The highest grade D, E and F color diamonds are extremely rare and valuable. As the letter grade progresses, very faint yellow tints become visible. Still, G-J color grades represent exceptional colorlessness.
Near Colorless Diamonds
Diamonds graded K, L and M have faint color that is barely detectable to the untrained eye. With grades N through Z, the yellow and brown hues become increasingly obvious.
While these “near colorless” diamonds have slightly lower value than the top color grades, they still exhibit beautiful brilliance and fire. The subtle warmth from the light-yellow tints can be quite attractive. Near colorless diamonds offer more affordable options for diamond jewelry.
Fancy Color Diamonds
Any diamond with a noticeable hue beyond the Z grade on the GIA scale is classified as a fancy color diamond. These diamonds exhibit color saturation ranging from light to extremely vivid, in a variety of hues.
Some of the most popular fancy color shades include:
| Fancy Color | Description |
|---|---|
| Yellow | Varying shades from champagne to deep amber |
| Brown | Light cognac to rich coffee colors |
| Pink | From blush pink to fuchsia |
| Blue | Sky blue to deep navy |
| Green | Pastel mint green to vivid grass green |
| Red | Pinkish red to blood red |
| Purple | Lavender to violet |
| Orange | Light peach to vivid orange-yellow |
| Gray | Smokey grays to black |
While considered “imperfect” to the rigid color grading scale, fancy colors are breathtakingly beautiful in their own right. The vibrant hues add striking personality. Red, pink and blue diamonds are exceptionally rare.
The Argyle Mine in Australia was the primary source for pink and red diamonds until its closure in 2020. This has made naturally occurring red and pink diamonds some of the most sought-after and expensive diamond colors.
What Causes Diamond Color?
The different colors in diamonds originate from color centers – atomic impurities or structural defects. Here are the main causes of color in diamonds:
– Nitrogen – This is the most common impurity found in diamonds, present in 98% of diamonds. When clustered in groups of two (N2), nitrogen causes faint yellow; when clustered in groups of four (N4), it causes intense yellow. Single nitrogen atoms (N) do not affect color.
– Boron – This element results in blue color. The more boron present, the stronger the blue color saturation.
– Hydrogen – Hydrogen impurities create a rare orange-pink to red color, depending on the amount of nitrogen present also. The combination of nitrogen and hydrogen is responsible for pink diamonds.
– Lattice Defects – Structural irregularities in the diamond crystal lattice can give rise to brown, yellow, green and other colors. Plastic deformation during crystal growth is linked to gray and black diamonds.
– Radiation Exposure – Diamonds can change color when exposed to radiation. Green diamonds get their color when naturally irradiated rocks alter the diamond’s structure. Irradiating a brown diamond can produce pink or red gems.
Are Color Treatments Used?
Some diamond colors are artificially enhanced or induced through treatments:
– HPHT – High pressure, high temperature treatment can make brown and yellow diamonds colorless or fancy colors like pink or blue. HPHT modifies the diamond’s internal crystal structure.
– Irradiation – Exposure to radiation turns brown diamonds green, yellow diamonds black, and can enhance blue shades. Neutron bombardment is used to produce colored gemstones.
– Coatings – Thin surface coatings can produce vibrant rainbow colors. However, coatings wear off over time.
Reputable jewelers will disclose any color treatments. Naturally occurring fancy colors are more prized than treated diamonds. When in doubt, ask for a lab certificate from GIA or AGS which tests for artificial color enhancement.
Choosing a Diamond Color
When selecting a diamond, color is a primary factor affecting beauty and value. Here are some tips:
– For a classic look, stick with colorless or near-colorless diamonds with grades D-J. The higher grades D-F will maximize sparkle with the least color.
– Fancy light yellow, brown or gray diamonds offer beautiful options at more affordable prices.
– Look for secondary hues like pink, blue or green to add unique personality. Make sure fancy colors are natural, not treated.
– For engagement rings, many prefer colorless for the pure white look. But enhanced yellow, pink or blue can also look stunning.
– Match the setting metal to the diamond hue, like yellow gold with yellow diamond or white metal with a colorless stone.
– Be aware of any color treatments and ask for full disclosure. Insist on a qualified lab grading report.
– View diamonds in person before purchase to accurately judge the color. Each diamond is unique.
Diamond Color Chart
This chart summarizes the GIA color grading scale, with equivalent colors:
| GIA Grade | Color Appearance |
|---|---|
| D-F | Colorless |
| G-J | Near colorless |
| K-M | Faint yellow |
| N-R | Very light yellow |
| S-Z | Light yellow |
| Fancy | Yellow, brown, pink, blue, green, red, black, orange, purple, gray |
Rarity of Diamond Colors
Here is an overview of the relative rarity of naturally occurring diamond colors:
| Diamond Color | Rarity |
|---|---|
| Colorless | Common |
| Near Colorless | Common |
| Light Yellow | Common |
| Fancy Light Yellow | Uncommon |
| Fancy Vivid Yellow | Rare |
| Pink | Very Rare |
| Blue | Extremely Rare |
| Green | Very Rare |
| Red | Extremely Rare |
| Purple, Orange | Very Rare |
| Gray, Black | Uncommon |
As shown, pure white and lighter shades of yellow are the most frequently seen diamond colors. Red, pink and blue are the rarest and most valuable fancy shades. Vivid saturation also greatly increases desirability and price.
Price Differences by Diamond Color
Diamond color significantly impacts the price per carat. Here are approximate price differences based on GIA color grades:
| Diamond Color | Price Per Carat |
|---|---|
| D-F (Colorless) | Highest price |
| G-J (Near colorless) | 10-25% less |
| K-M (Faint yellow) | 25-50% less |
| N-R (Very light yellow) | 50-75% less |
| S-Z (Light yellow) | 75%+ less |
As you go down the normal color scale from D to Z, prices gradually decrease. But once you enter fancy colors, values can shoot upwards exponentially for rare vivid pink, blue, green or red diamonds.
Conclusion
Diamonds exhibit an array of colors, starting from prized pure white to varying shades of yellow, brown, gray and on to the rare fancy colors like pink, blue and red. While colorless grades D-F are the most valuable, fancy colors add special character. Make sure any enhancement treatments are disclosed, and buy certified diamonds with lab grading reports. Consider the setting and your personal preferences when choosing diamond color. An informed buyer can select the ideal color to fit their budget and style.
