The ultimate guide to buying a black diamond in South Africa

One of the big trends we saw in South Africa in 2023 was the increased popularity of black diamonds. More and more couples are looking for alternative gemstones to set in their engagement and wedding rings, and black diamonds are the perfect choice for many reasons. For many years, men’s jewellery lines have featured black diamonds and now, women are seeing the allure and appeal of these diamonds.

Because black diamonds have not been marketed as heavily in South Africa as “traditional” white diamonds, many shoppers are confused about what to ask for or look for, when buying a black diamond. Katannuta Diamonds has all the information you need to make an informed buying decision.

A triangular cut black diamond.

Are black diamonds real diamonds?

Yes, black diamonds are real diamonds and occur in nature. Naturally occurring black diamonds are relatively rare and predominantly found in Brazil and the Central African Republic (CAR). A significant proportion of black diamonds in the marketplace are natural diamonds of dark grey tones that have been treated (using high-pressure, high-temperature techniques) to induce a uniform black colour. Whether you’re looking at a natural black diamond or a treated black diamond, both are real diamonds.

What gives a black diamond its colour?

Black diamonds are inherently imperfect, heavily included diamonds. Natural black diamonds get their colour from large quantities of mineral inclusions such as graphite, pyrite and hematite distributed throughout the diamond. These inclusions often occur as clouds, and natural cracks and fractures throughout a diamond may become graphitised, giving a diamond a dark grey, opaque appearance.

Are black diamonds expensive?

Despite being considered a Fancy colour, black diamonds are perhaps the most affordable coloured diamonds, bearing in mind that most are treated. Natural, or untreated, black diamonds are more expensive than treated black diamonds but are still relatively affordable. In South Africa, a 1ct treated black diamond will cost you approximately R7,000 (based on the March 2024 rand-dollar exchange rate).

An oval shaped black diamond ring is an affordable way to make a statement.

Should I consider the 4C’s when buying a black diamond?

The classic 4C’s guidelines that apply to purchasing a white diamond don’t apply to black diamonds, but there are some things to look out for. The universal GIA colour scale that everybody knows applies only to colourless and near-colourless diamonds (D-Z colours). Because black diamonds fall outside this colour range, this colour scale does not apply to them. Additionally, because black diamonds are opaque and heavily included, they aren’t graded for clarity either. Do bear in mind however that many black diamonds (both natural and treated) may have visible imperfections and fractures that reach the surface of the diamond.

A natural black diamond ring showing visible cracks, ruts and fractures on the surface of the diamond.

What shapes are black diamonds cut into?

Black diamonds are commonly available in all regular diamond shapes, including rounds, ovals, cushions, pears, marquise, and emerald cuts. Black diamonds can also be cut into rose cuts and unique shapes such as kites, hexagons, and shield shapes. Colourless diamonds are cut into a variety of common shapes with well-defined mathematical proportions, geared towards maximising the sparkle, fire and brilliance of the diamond. Given that black diamonds are opaque, there is no sparkle to speak of and as a result, normal cutting proportions are often discarded.

If you look at a range of black diamonds, you may see huge variations in the proportions of the stones. Some brilliant-cut black diamonds may have a high crown angle or a very small table. Make sure any black diamond you purchase isn’t a very deep stone and avoid high crown angles – these factors will lead to heavier diamonds that will cost you more but look smaller in size.

Kite, round, oval and emerald-cut black diamonds.

Are black diamonds good for engagement rings or wedding bands?

Absolutely! Black diamonds, like colourless diamonds, have a hardness of 10 out of 10 on the gemstone hardness scale. They are tough, durable gemstones that are very resistant to wear and tear and as such, can be worn daily in a ring without too much chance of damage. A black diamond can be used to create a striking engagement ring when matched with white diamonds, and small black diamonds are perfect for eternity or wedding rings.

A hexagon cut black diamond ring in yellow gold and a black diamond eternity ring in rose gold.

Are you ready to consider a black diamond engagement ring? Katannuta Diamonds has numerous black diamonds in stock, in a variety of sizes and shapes, and we’ll create a unique engagement ring for you. Browse some of our previous designs here or contact us with an idea you have and let us create a show-stopping black diamond ring for you.