The most famous gemstone in the world.
Said to be “a girl’s best friend”, the name derives from the ancient Greek word ‘adamas’ meaning invincible.
In the gem world, more people are employed in mining and cutting Diamonds, than for any other gemstone. The quality of this gem’s colour, clarity and cut are more tightly measured than for any other gemstone, and although there are various standards used across the globe, that of the Gemological Institution of America (GIA) is the most widely used.
Diamond is a gemstone made of pure, native crystallised carbon. The value of a similar carat weight of Diamonds can vary dramatically, based on their clarity and colour - and to some extents more importantly - how well the gemstone has been cut.
As the hardest natural mineral known to man, measuring 10 on the Mohs scale, Diamonds can only be cut and faceted by other Diamonds, and although they are extremely hard, they are also quite brittle, making them one of the more difficult gems for lapidarists to shape.
Its very high refractive index (2.4175–2.4178) is what gives the gem its famous sparkle; its strong lustre is described as an adamantine lustre. One of the main differences to other gemstones is that a lack of colour is highly prized. The closer to colourless a Diamond becomes, the better dispersion (the splitting of light into its constituent colours) it will display.
Until the late 1800s, Diamonds were among the rarest gemstones on the planet, and due to their incredible hardness, coupled with the belief that cutting them would reduce their magical powers, were often not faceted. Unlike biblical gemstones such as Amethyst, Topaz, Ruby, Sapphire, other than records by Pliny the Elder AD 23 – 79, very little was documented about Diamonds until the 14th century. In fact, it was not until this period that the first rudimentary facets were being applied to the gem. As many Diamonds are octahedral in shape (imagine two Egyptian Pyramids being attached to each other at the base), by simply adding a table facet, many early cuts closely resembled the outline shape of today’s “Brilliant Cut”.
Then, in the late 1800s, everything began to change with the discovery of Diamonds in South Africa. In a very short period of time, gems from this region would account for over 90% of those on sale. Through huge marketing campaigns by the owners of these new deposits, the new kid on the gem block went from being fairly unknown, to unquestionably the global leader within half a century!
For those interested in studying advertising and marketing, the rise of the Diamond to the status of “the world’s most popular gemstone” (overtaking many rarer, more colourful gems, gems who have been linked with royalty, religion and powerful leaders for thousands of years, gems who are steeped in folk lore and legend), is a real textbook marketing campaign.
The youngest Diamonds are believed to have been formed over 100 million years ago! They crystallise when carbon is put under immense pressure of between 45 and 60 kilo bars and at a temperature ranging from 900 - 1300 degrees Celsius. For these conditions to occur naturally, it is believed that Diamonds were created some 90 to 120 miles beneath the Earth’s crust. This means that they actually form while still inside the mantle, an area made up of hot flowing magma. The only other valuable gem on the planet to crystallise under these hostile conditions is Peridot. Once gem hunters understood that Diamonds were transported to the surface of the Earth in old volcano pipes, now known as kimberlite pipes, more discoveries shortly followed.
Although Africa is still a major supplier of Diamonds, today it holds less than 50% of the market share, and it cannot control the market as much as it once did. New big players on the scene include India, Canada, Russia, Australia and Brazil.
It’s taken for granted that the larger the carat weight of a good quality gem, the larger the price, but why is this the case? In simplistic terms, larger gems are rarer than smaller gems and in the case of Diamonds, only one in a million faceted Diamonds are said to weigh over one carat.