Friday, October 4, 2013
The Story of Diamonds
Man – and woman – has had a love affair with diamonds for thousands of years. They have been used for decoration, as protection and, these days, as an expression of love, as we see in the stunning diamond engagement and weddings rings that seem to be all around us. But what is the real story of diamonds?
How are diamonds formed?
Diamonds are composed of pure carbon, the most common element on the earth. Their story begins over three billion years ago when carbon deposits deep in the earth were subjected to pressures and temperatures so extreme that they began to crystallise. The earth’s surface began to cool but volcanic activity caused magma (liquid rock) carrying the carbon crystals (which we now call diamonds) to flow to the surface. As the magma hardened, so the diamonds became encased vertical volcanic ‘pipes’.
Over millions of years, the rock has been eroded away, freeing the diamonds and leaving them to be washed into watercourses and sometimes down to the sea.
Diamonds are renowned for their hardness and are the hardest substance known to man. They are rated at 10 on the Moh’s scale of mineral hardness with corundum (the second hardest material and from which rubies and sapphires are formed) rated at 9, making them four times harder in absolute terms. Diamonds cannot be scratched by anything other than another diamond. They can, however, be split or even shattered by a sharp blow in the right place, a property exploited by diamond cutters when turning the raw stone into beautiful jewellery.
Diamonds through the ages
The first record of diamonds is in India over 3,000 years ago. Hindus believed that they had extraordinary powers and wore them as talismans to ward off evil. They even placed them as eyes in statues of their deities. The ancient Greeks and Romans also valued diamonds as bringers of good fortune and believed that they were tears of the gods. In the Dark Ages diamonds were thought to have healing powers - holding a diamond in the hand while making the sign of the cross was thought to cure illness and heal wounds. By the Middle Ages, diamonds came to be valued more for their beauty and value rather than their mystical powers.
As their popularity and value increased, mine owners liked to perpetuate the myth that they were poisonous to deter mineworkers from stealing stones by swallowing them.
Nowadays, most people consider the diamond to be a beautiful and valuable gemstone. It is popularly viewed as a symbol of love and eternity and so is used in engagement and wedding rings as the gemstone of choice for many couple.
Sources of diamonds
In the distant past most diamonds came out of India, where two of the world’s most famous diamonds – the Koh-I-Noor and the Blue Hope – were found. But as India’s production dwindled so new mines were found in Brazil and Borneo. Again these were too small to satisfy demand. In the mid-19th century, diamonds were discovered in great quantities in South Africa and later in Australia where the world’s richest deposits are to be found. Indeed, Lake Argyle (in the remote northern part of Western Australia is now the world’s largest producer by volume although very few gem quality stones are found.
Jenny McFarland is interested in the history of jewellery through the ages.
A crystal is a solid material whose components are arranged in a highly ordered microscopic structure that forms a crystal lattice extend...