Eight hundred kms north of Adelaide, in South Australia, a small town stands in the Outback: Coober Pedy. Its name comes from the Aboriginal term kupa-piti, meaning “white man’s hole”. The town is arid, flat and the heat can reach 45° in the shade during summer. It is home to 1500 people and the majority of them live in underground homes called dugouts. These excavated hollows in the sandstone offer residents a respite from the extreme conditions. The reason they exist is the same reason the town exists: opal mining. Opal is one of the most valuable gemstones in the world. Its price can reach into the millions, depending on type, color, and weight. Black opal is the most prized opal, it can reach over AUD $15,000 a carat. The gemstone was first found in Coober Pedy in 1915, leading to a mining boom as people came in search of their fortune. The most expensive recorded Australian Opal is the “Olympic Australis,” weighing an astonishing 17,250 carats.
This massive opal specimen comes from Coober Pedy and was valued at $1.7 million USD., making it the most expensive opal in Australian history. It’s estimated that 95% of the world’s Opal comes from Australia and in particular 70% from Coober Pedy. Each piece of Opal is “One Of A Kind” and can never be replicated or reproduced. The truly phenomenal thing about Opal is that it can display all of the colours of the spectrum. The “play of colour” found in Opal is the result of interference and diffraction of light passing through tiny silica spheres in the microstructure of Opal. This means the bright rainbow colours of Opal, as they appear to the human eye, will move and change dramatically depending on the angle at which the stone is viewed as light refracts the silica spheres.