Planet Earth provides the perfect conditions to compact and heat carbon atoms in order to make diamonds. Those conditions are found starting at 200km below the surface. Diamonds have their natural home between there, and up to at least 800km deep. The gems form within rocks called eclogites and peridotites, and they comprise what is known as the Earth’s mantle.
This gems form within rocks for which Planet Earth provides the perfect conditions to compact and heat carbon atoms in order to make diamonds; such conditions found at 200km below the earth’s surface. Diamonds are found naturally between 200km and 800km deep, forming within rocks called eclogites and peridotites, comprising what is referred to as the Earth’s mantle.
It may be that the carbon is originally drawn from the iron core of our planet. Diamonds inevitably hold important clues to the evolution of earth itself.
A spectacular slice through the Earth allows us to identify the rocks that rise to the surface from the core of which, analogy and meteorites show us the probable composition, as in the case of the extraordinary slice of the Argentinan Esquel meteorite, studded with green gem-quality peridot crystals.
A beautiful light show evokes the internal dynamics of the Earth, which is shaped by masses of flowing rocks, apparently immobile throughout the course of a human life but in fact, moving at an incredibly slow pace in terms of geological time span.
Diamonds may be formed deep below ground, but they are frequently found on the earth’s surface. Explosive eruptions of staggering force catapult diamonds from the core to the earth’s surface at the speed of sound. Kimberlitic eruptions refer to lava which sucks diamonds from their host rock and elevates them to the surface.
Kimberlites, discovered at the end of the 19th century, were so named due to their origin; Kimberley, South Africa. Kimberlites are often worn away by erosion to expose diamonds, and the extremely hard-wearing diamonds are found within gravel beds, such as the alluvial deposits which provide us with diamonds in India, Brazil, Borneo, central Africa and Namibia.
Central India is believed to be the original diamond discovery three thousand years ago, when Hindus mined them from the sand in stream beds. At such time, diamonds were ‘polished’ by rubbed them against one another, as if ‘tumbled’ until they were considered to be acceptably polished. Diamonds were discovered in Brazil in 1725 in such vast quantities that the Portuguese government imposed heavy taxes upon diamond miners, in order to prevent depreciation in the value of diamonds. The diamond fields of Brazil remained the most prolific in the world until the young Boer boy made his discovery in South Africa more than 150 years later.
Diamonds are also formed within stars. This amazing finding resulted from the discovery of miniscule diamonds embedded in certain meteorites, in particular one which fell on the French village of Orgueil. The diamonds in these meteorites were found to be older than the solar system. This means that the diamonds came from a drifting cloud that crossed the solar system while it formed, and the diamonds were incorporated in the rocks as they aggregated. Billions of years later, these diamond-studded rocks fell from the skies onto our planet. It is since then deduced, that these diamonds originated from the final dying moments of some ancient, far-off star.
Supernova explosions actually project carbon atoms into space; the carbon atoms were themselves originally formed from nuclear reactions in the heart of the star.
The unique formation mechanism of these diamonds gave a clue to research engineers, who finally managed to replicate the process and make diamond within gas plasma, in the same way as it is made in stars.