What Are Black Diamonds | Black Diamonds Price

While they don’t sparkle the same way white diamonds do, black diamonds provide stunning contrasts in all kinds of jewelry. Black diamonds can dress up or dress down an outfit and provide a desirable alternative to other opaque gemstones such as black onyx. When paired with white diamonds, black diamonds have an elegance uniquely their own. In recent times their popularity has grown, but what most people don’t realize is that these diamonds are not actually black at all.

So if black diamonds aren’t actually black, what are they?

Like almost all fancy coloured diamonds, uniformly opaque natural black diamonds are extremely rare. They are technically white diamonds that are densely included (mostly graphite). They appear opaque because of their “polycrystalline” structure of the inclusions which prevents them from reflecting light. A natural black diamond is usually given the colour grade ‘Fancy Black’ by gem labs such as the Gemological Institute of America (GIA).

Treated black diamonds come in all shapes

Due to the comparatively high price and scarcity of opaque natural black diamonds, almost all the black diamonds you see in jewellery today are treated black diamonds. Treatment comes in many forms - in the form of irradiation, heat or surface diffusion and is done to enhance their black colour.

The treatment process actually turns the natural diamond to become a green that’s so dark it appears almost black, but not opaque. The treatment process doesn’t affect the durability of these diamonds, however, because ‘black’ diamonds are heavily included and porous, they’re harder to cut and polish. This can result in blemishes and nicks on the surface of many black diamonds. When buying black diamonds, make sure the surface of the diamond is smooth and well polished. There are multiple and varying quality grades, even amongst the treated black diamonds.

How much do black diamonds cost?

The price of black diamonds is much lower than that of white diamonds in all grades, mainly because of their colour treatment. They are thus categorised as colour treated natural diamonds. Typically, a 1 carat round treated black diamond with a nice make and very good polish (no surface blemishes) will cost in the vicinity of US$300 - US$600 per carat depending on opacity and uniformity of the black colour. In contrast, a well made untreated one carat “near colorless” diamond with an average clarity, such as VS1 or VS2, will cost approximately US$6,000 — US$9,000/ct.

Remember, natural black diamonds that are opaque and dense black are prized because they are untreated and rare, so expect to pay a substantial premium for them, much over equivalent sized treated black diamonds. They are still considered treasures from Nature and have taken hundreds of millions of years to form.