Australian Government | Opal – Australia’s National Gemstone
- Australia’s Opal fields are larger than all the Opal fields in the rest of the world combined.
- Types of Opals found in Australia
- Precious Opal displays play-of-colour
- Common Opal does not exhibit a play-of-colour (aka Potch Opal by Australian Miners).
- On 23 July 1993, the Governor-General, the Hon Bill Hayden AC, proclaimed the opal as Australia’s national gemstone.
- In Aboriginal dreamtime stories, the Opal was created when the colours of the rainbow touched the earth.
- Australia is the only place in the world where you can find Opalised animal fossils, there are also many examples of opalised plant fossils.
- In 1994 the Australian Women’s basketball team adopted the nickname “The Opals”.
Australia’s Iconic Opals
- 1915: Pride of Australia aka Red Emperor
- Found 1915 at Lightning Ridge, NSW.
- Shaped like Australia.
- By 1954, it had toured at least five World Fairs as “the greatest opal of Australia”.
- 1938: Aurora Australis
- Found 1938 at Lightning Ridge, NSW.
- Considered the world’s most valuable black opal.
- 1946: Fire of Australia
- Found 1946 in Coober Pedy, SA.
- World’s finest uncut opal.
- Weighs 998g – size of two cricket balls.
- 1986: Halley’s Comet o Found 1986 at Lightning Ridge, NSW.
- Found about the time Halley’s Comet appeared in Australian skies.
- Recorded as the world’s largest uncut opal.
- 1989: Galaxy Opal
- Found 1989 in Jundah, QLD.
- One of the largest and finest quality boulder opals ever mined. The Start of Opal Mining in Australia
- 1890 Precious opal mining begins in NSW.
- 1896 Precious opal mining begins in QLD.
- 1913 Precious opal mining begins in SA.
- 1926 Minnie Berrington was one of Australia’s first female opal miners.
Science Key Facts
- Chemistry: SiO2nH2O
- Hydrated Silica: Opal is a type of mineraloid
- In 1965 CSIRO scientists discovered that the voids between opal silica spheres caused light to be diffracted to create the play-of-colour, as seen in a rainbow.
- Opal has a play-of-colour due to millions of tiny silica spheres of different sizes.
Image Source: M.Berrington – Emil Otto Hoppe Estate Collections, Opals – Geoscience Australia
Reference: Department of the Prime Minister & Cabinet, Geoscience Australia, Opals Down Under & SA Museum.