Diamond

Pure diamond is extremely valuable for its potential to be used in jewellery, while lower quality diamond is valued for its unique strength and conductive abilities.
Diamonds are formed far below the surface of the earth, anywhere between 150 and 190 kilometres inwards, at enormous temperatures and pressures that turn carbon into diamond.

Diamonds were brought to the surface during volcanic eruptions many millions of years ago, when magna was forced up through the earth. These eruptions created the kimberlite pipes, which are named after the area in South Africa called Kimberly. Kimberlites are a kind of igneous rock, the umbrella term for all rocks that are found around cooled magma or lava.

Diamonds were not held in the magma, but were in deeply-formed rocks and minerals that the magna carried upwards. When the magma finally cooled, it left veins in the earth that held the diamond deposits. Miners look for blue-tinged rock to suggest the location of diamond deposits.

Over time diamond deposits can disperse as the rock erodes and is moved by water and land shifts. When diamonds are found outside veins, like in riverbeds, they’re called alluvial diamond sites.

Diamonds were first discovered in Australia in 1851 near Bathurst in New South Wales. There were also alluvial deposits found and mined in Copeton, Bingara and Cudgegong in north-eastern NSW from 1827 to 1922. Limited mining restarted here in 1997. Serious diamond mining began in Australia when places in the Kimberley region of Western Australia were identified as potential areas for diamonds deposits, due to their similarity to the Kimberley region in South Africa. Exploration in the 1970s found some low quality pipes, then in 1979 diamond samples were found in a creek leading to Lake Argyle, then traced until the Argyle deposit was discovered.

The Argyle deposit is where 90% of Australia’s diamond production is carried out and is the world’s largest diamond deposit. Its diamonds however are mostly low quality, with only 5% of its production rated as gem quality, while 40% are almost gem quality, and 55% is industrial grade.
The Argyle mine supplies approximately 20% of the world’s natural production of diamonds.

The Argyle mine’s most valuable product is its famous pink diamond. These are cut and polished in Perth at the Argyle Diamonds company base.

Higher quality diamonds were mined in smaller pipes at Merlin in the Northern Territory, which had a strikingly high percentage of gem-grade diamonds – 65% of its product. This mine only operated for three years between 2000 and 2003, in which time it produced around 100kg of high grade diamond.

There is also a mine in Ellendale that produces a small quantity of yellow diamonds. The Ellendale mine is owned by the other major diamond company in Australia, the Kimberley Diamond Company. Australia has around 16% of the world’s industrial quality diamond resources. This is the third largest resource percentage, following The Democratic Republic of Congo and Botswana. Australia’s diamond exports are worth about $600-700 million a year.

Diamond is the hardest material known to us. Its lattice formation, in which every atom is connected to four or more others, gives it its strength. Diamond also has the greatest conductive ability of any bulk material.

Oddly enough, this isn’t what makes diamonds so popular. Instead, diamonds are most valuable for their ability to disperse light – essentially, to sparkle – making them prized as gemstones, and used in every kind of jewellery imaginable as a mark of high quality and value.

Gemstone grade diamonds comprise a small percentage of the overall diamond mined. Industrial grade diamonds make exceptional cutting tools, and are often used to make diamond knives and anvil cells. Diamond knives are knives tipped with diamond, and are used medically and scientifically when an incredibly sharp and durable edge is vital to the work. A diamond anvil cell is a tool used for science experiments to compress tiny materials to extremely high pressures. This helps scientists recreate what it was like inside forming planets.

Diamonds come in many different colours. While purest diamond is colourless, tiny defects can happen during its formation, making it appear blue, green, yellow, pink, red or brown, depending upon what causes the impurity. One thing is for certain – every diamond is unique in colour, structure, cut and sparkle. And oh, those things sparkle!