Research could revive Australian opal mining

A team of geologists from Sydney University has released promising findings for the development of a new land analysis technique that could benefit Australia’s declining opal mining industry.
Opal is Australia’s national gemstone, with Queensland’s Great Artesian Basin producing over 90 per cent of the world’s supply.
However, no significant gem sources of have been discovered within Australian territory since the 1900s; unlike gold exploration, there are no widely accepted strategies or concepts available to guide opal miners to new prospects.
Australia’s known opal fields have become progressively barren, particularly in the last 20 years, with mining ventures becoming increasingly expensive but less fruitful. An article published in the Journal of Australian Earth Sciences and in Computers and Geosciences, revealed an innovative data collection methodology developed by scholars in Sydney, involving the comparative analysis of the geological history of known opal fields, particularly within the Great Artesian
Basin, with other Australian areas of similar geological exposure.
“The geological conditions under which opal formed resulted from a very particular sequence of surface environments over geological time,” the team’s data mining expert Dr Thomas Landgrebe said.
Occurring from about 145 million years ago, the conditions for opal development involved alternating shallow seas and river systems, followed by uplift and erosion.
Following this trend of geological history, the team hypothesised the most likely locations for new opal fields, speculating potential in the south-western extent of the Great Artesian Basin in South Australia, in a northwest-southeast corridor throughout central Queensland, and in areas around Lightning Ridge in north-central NSW.
The findings reputedly have the potential to revive Australia’s opal industry.
Opal is an aesthetic stone which can express every colour within the visible spectrum. Demand for opal is driven purely by its appeal as a decorative gem, as it maintains no apparent industrial applications.