If you’ve fallen in love with the idea of a black diamond engagement ring, you’ll want to do your homework to ensure you purchase the perfect gem. Black diamonds are unusual, shrouded in mystery and make for eye-catching pieces. Here’s everything you need to know about them.

VIEW BLACK DIAMOND JEWELLERY

THEY ARE NOT A COLOURED DIAMOND

A fancy coloured diamond like pink and yellow diamonds get their unique hues from the minerals they are exposed to while forming. Black diamonds, however, are not ‘coloured’ at all. Instead, they are closer in composition to pure white diamonds than they are fancy-coloured diamonds.

While white diamonds are clear, sparkling stones, black diamonds are opaque. This is caused by the high amount of inclusions, or clusters of graphite, in the diamonds. The high levels cause the gem to appear black. Unlike white diamonds, black diamonds don't shine by reflecting light. Instead, they absorb light, giving them a unique marble-like allure.

Black diamonds are as hard as white diamonds, the graphite inclusions tend to make them more brittle. Their unique composition means they are notoriously hard to cut, and it can take up to a year for a diamond cutter to complete a diamond. When you wear your black diamond engagement ring you can be assured that a lot of patience and love went into the cutting of the black diamond.

WE DON’T REALLY KNOW WHERE THEY COME FROM….

There are a few facts that we can confirm. We know black diamonds were formed up to 3.8 billion years ago. Unlike other diamonds, which are sourced from below the earth’s surface, black diamonds are typically mined from the beds of streams and are only found in Brazil and parts of Central Africa. Only three metric tons have ever been mined, making them very rare. Black diamonds were first discovered in Brazil and were named ‘carbonados' by Portuguese settlers. They used the term because of the burnt (carbonized) appearance of the raw stones.

The limited locality of black diamonds has the science divided because it points to a different origin story. Some believe black diamonds formed through radiation, while others have proposed that black diamonds were formed in outer space and were left on Earth when an asteroid crashed millions of years ago. The fact that not everyone can agree on how black diamonds came into being adds to their mystery.

Black diamonds are exceptionally hard, which makes them challenging to cut. When they were first sent to foreign shores in the 19th and 20th centuries, jewellers didn’t always welcome them. But this hasn’t stopped them from being fashioned into some of the most famous jewellery pieces we know of.

FAMOUS BLACK DIAMONDS

One of the most famous black diamonds is known as the Black Orlov diamond. The origin of this dark steely grey-coloured 67-carat diamond isn’t known but was originally part of a 195-carat black diamond gem. It was set into an idol in India before being stolen.

India has always held black diamonds in awe. They were traditionally considered to be cursed, reportedly because they looked like the eyes of snakes and spiders. However, not all black diamonds have dark associations.

In Italy, couples believe that if you touch a black diamond, an ailing relationship can be saved as the diamond ‘absorbs’ the problems you are experiencing. The world's biggest known black diamond, the 88-carat Korloff Noir diamond, is considered to hold similar properties. It’s thought to bestow good luck and happiness on anyone who touches it. Before it was polished, this famous black diamond had 421 carats.

HOW BLACK DIAMONDS ARE GRADED

The cut of a black diamond is important, as you want to achieve a design that allows the maximum amount of light into the diamond. Because black diamonds are opaque, they can't be graded on the GIA clarity scale.

The GIA does not issue grading reports for black diamonds, but your jeweller will be providing you with a diamond certification. The report will note if the colour is natural or treated. This is important as not all black diamonds are ‘natural’.

Treated black diamonds are created using genuine colourless diamonds that are exposed to treatments such as irradiation or heat to give them the black shade. These are referred to as ‘colourless treated black diamonds' or ‘black coloured diamonds'. You may also come across ‘simulant black diamonds' or manmade black diamonds. These are made in a laboratory. As with all diamonds, if you are shopping for a black diamond engagement ring always ask the jeweller for a certificate for the gem.

When you inspect a black diamond, the 4Cs of diamond grading, are colour, clarity, cut, and carat weight. This is combined with the GIA's International Diamond Grading System. These are the standards by which colourless to near-colourless (D-to-Z colour diamonds) are graded. Because black diamonds fall outside of this shade range, their colour is based on GIA's colour grading system for coloured diamonds.

Most black diamonds you will find are graded around the 1-carat mark. The diamonds are denser than colourless diamonds, so note a 1-carat black diamond will be smaller than a 1-carat colourless diamond. When buying a black diamond look for a mirror-like surface.

ACHIEVING YOUR DREAM RING

We have a wide selection of cuts available for black diamonds, including round, princess, cushion, marquise, pear, heart or cushion. Black diamonds lend themselves to being paired with white diamonds. It makes for a graphic contrast, but the white diamonds also draw light towards the diamond.

If you’re looking for celebrity inspiration, one of the most popular black diamond engagement rings was featured in the hit show, Sex and the City. In the show, Carrie’s boyfriend Mr. Big, presented her with a 5-carat black diamond engagement ring. The ‘Carrie ring' featured a black diamond set in 18K white gold and accented with 80 pave-set diamonds.

It’s also important to consider the metal you choose for black diamond jewellery. Because of its bold, powerful colour, black diamonds work well with 14k white gold, platinum and other white metals.

LA Ink star and tattoo artist, Kat Von D chose a custom-made black diamond engagement ring. The centre of the ring was mounted with a black diamond and flanked by two skulls. Carmen Electra's 2008 black diamond engagement ring, which featured a round black diamond, was set in a six-prong setting. It was anchored in a diamond pave band. *NSYNC singer Lance and his partner wear matching engagement rings. They feature two rows of channel-set black diamonds in a yellow-gold setting.

As you can see, black diamonds are unique and lend themselves to unusual and custom-made pieces. As with white diamonds, they represent love and commitment but come with the added associations of passion, action and energy.

BUY A BLACK DIAMOND RING

Black diamonds lend themselves to unique designs and eye-catching rings. Shimansky is renowned for their exquisite black diamond rings. Find a Shimansky Store near you.