Opal (not the NSW government opal travel card) is Australia’s national gemstone.
Australia’s national gemstone is the opal, a stone famous across the world for its brilliant colours. In Indigenous stories, a rainbow created the colours of the opal when it touched the earth.
Australia is home to the world’s highest quality, precious opal. The most famous is black opal from Lightning Ridge in New South Wales. Black opal has a colour play of red, green, blue, violet, magenta or yellow against a dark background.
An opal is a ‘gemstone’ – that is, a mineral valued for its beauty. Gemstones are most often used in jewellery. Examples of gemstones include diamonds, rubies, emeralds, sapphires, jade, opals and amethysts.
Gems stones generally get their colour because of certain metals contained in the mineral. For example purple amethyst is quartz containing tiny amounts of iron. However opals are unique because they display a rainbow-like display. This is due to their intrinsic microstructure which diffracts white light into all the colours of the spectrum.
Opals are mined across Australia although you need an opal mining permit for mining opal in most areas to do this. Coober Pedy is one of the richest sources of opal in Australia. Many people undertake training in opal cutting and polishing to produce consistent standards and quality.
Australia’s opal fields are bigger than those found in the rest of the world combined. Opal production was worth $47 million to Australia in 2007-2008. Crystal gemstone cutting supports many communities in South Australia, New South Wales and Queensland.
Australian opals are valued for their stability as well as brilliance. Opals from other countries are associated with volcanic rock. These gemstones have high water content and tend to crack or craze during cutting or polishing, or during hot or dry conditions.
Australia’s precious opals include black opal, white opal, crystal opal, fire opal and boulder opal.