What image first comes to mind when you think about a diamond? It is likely that you envision the colorless variety. Diamonds are composed of carbon; the more colorless, the purer the stone’s molecular composition. Colorless stones are graded according to the GIA’s D-to-Z scale of normal diamond color. A grade of D represents an ideal untainted colorlessness while Z denotes yellowish stones which are one step from being considered a “fancy” color. Diamonds with higher color grades are more valuable, and, the further down the alphabet you go, the lower the value of the stones.
This all changes dramatically once you get past Z. All diamonds, regardless of their hue, whose color falls outside this normal D-to-Z range are considered “fancy”. These fancy colors can be striking and very expensive. They are also quite rare, with some experts estimating that only 2% of natural diamonds qualify as fancy. Different colors are created naturally for numerous reasons and subsequent treatments can further change their color. Let’s take a quick look at these fancy diamonds and what makes them special.
Red, Pink, and Purple:
• I clump reds and pinks together because they are usually found together. These colors result from what scientists call graining. Graining describes bands in which color is concentrated. The primary source of these diamonds was the Argyle Mine in Australia. Argyle began operations in 1983 and ceased production at the end of 2020. This is unfortunate, as Argyle was the most consistent global source of pinks and reds. Red was already the most expensive fancy colored diamond per carat before closure. They famously hosted an exclusive yearly sale of the best pink and red stones. Without this mine, you can expect the availability of these stones to drop.
• Pure purple diamonds are extremely rare. As with reds and pinks, purple is caused by graining. Most, purple stones are modified with hints of pink.
When it occurs in a pure color, orange is perhaps the rarest of all naturally occurring hues. It is so rare that scientists still don’t understand what exactly causes it. Orange color usually shows up as a modifier to other colors. You will find pinks and reds with orange undertones.
Brown diamonds are the most common of all fancy colored stones. This means that they are also among the most affordable. Their color results from irregular crystal growth. Although they have been used in jewelry for millennia, recent rebranding of brown stones as “champagne”, “chocolate”, or “cognac”, has greatly boosted their popularity. Unlike some other fancy colors, brown diamonds can have a beautiful, deep color.
Yellow diamonds are the second most common colored diamonds after browns. The color can be caused by the presence of nitrogen, gaps between carbon atoms, and, at times, hydrogen. Because yellows are relatively commonplace, you will see them on the market in an abundance of different cuts, sizes, and color saturations.
Rare green diamonds are usually light in tone with relatively low color saturation. The color is often modified with greys and browns. You will not find diamonds with the deep greens that we associate with emeralds or tourmalines. Naturally occurring green color in diamonds stems from exposure to radiation. This radiation may come from the ambient environment in which the diamond grew or a stone can be artificially exposed after it is mined. This leads to some complicating issues. First, since the color comes from an outside influence, the green hue is usually restricted to the outer region of the diamond and doesn’t penetrate deeply into the crystal. This makes it difficult to cut and facet stones because there is a risk that the color can be polished away if it is shallow. Also, the stone itself may be radioactive and should be tested before being put on the market.
A select few green diamonds which also contain hydrogen are classified as “chameleon diamonds”. These stones will temporarily transition to a yellow color if exposed to high heat or if they are left in the dark for long periods of time. They will always return to the base green hue.
Blue and Violet:
• Most blue diamonds result from the presence of boron amongst the carbon crystal structure. They are technically considered Type IIb stones. It is hypothesized that radiation, hydrogen, and special inclusions can rarely lead to blue colors as well. Even the best blues have a greyish undertone and you will not see the deep and pure color saturation that is present in sapphires. One of the most famous diamonds in the world, the infamous Hope Diamond, is one such gem.
• Type IIb diamonds described above as blue may alternatively present as violet. Violets are another color that is quite rare. Interestingly, the Argyle mine was one of the primary producers of these stones as well.
White, Grey, and Black:
Technically speaking, white, grey, and black are “achromatic”, or without color. These three species of diamond all have different origins.
- White diamonds occur when there is an abundance of extremely small inclusions which scatter the light to give it a milky effect.
- When it comes to greys, scientists believe that the color often stems from high levels of hydrogen.
- Black stones result from large amounts of dark inclusions and contain vast networks of tiny fractures. These issues impact the stability of the stones, making them inherently brittle when compared to other diamonds. Many blacks began life as greys and have been treated with high temperature and high pressure to further darken the stone. Others are the result of irradiation. You will see black diamonds on the market and can absolutely wear them as jewelry, just remember that they are a delicate stone and should be treated with extra care.
Synthetic Colored Diamonds:
This article would not be complete without a quick note about synthetic diamonds. Synthetic diamonds are chemically and optically identical to natural diamonds. The difference is that they are grown artificially. Some newer synthetics are so convincing that can only be identified by a professional grading laboratory. You will find lab-grown diamonds in almost as many colors as natural ones. Also, they can be significantly more affordable than their natural counterpart. It is not uncommon to find lab-grown stones discounted 30% and higher. If you are on a budget but have your heart set on a fancy-colored diamond, synthetics are a great alternative!