A notice from the government states that small-scale mineral claims granted or transferred between January 2015 and February 2023 are affected.
The notice confirms that miners must cease all activities until they can obtain a new mineral claim.
The NSW Natural Resources Minister, Courtney Houssos, revealed this week that a review found 827 miners in Lightning Ridge and 31 in White Cliffs were granted invalid mining licences.
The review discovered the error was due to ‘a range of issues’ caused by reforms made in 2015 to the Mining Act 1992.
"On behalf of the government. I apologise for this disruption to miners and landholders," she said.
"We know how important the opal industry is to Lightning Ridge, White Cliffs and surrounding communities."
According to reporting by ABC News, the review uncovered a total of 3,343 mineral licences which had been deemed invalid.
Houssos said the government plans to run an additional independent review into the current rules surrounding small-scale opal licences.
"This review will analyse the current state of the industry, including access and landholder compensation arrangements and will consider the findings and recommendations of the 2011 Murray Wilcox report to inform practical changes to the legislative framework,” she said.
"I look forward to visiting Lightning Ridge when parliament rises to meet in person with miners and landholders to gain a firsthand understanding of opal mining and work with them to identify improvements to the current framework."
Australia is responsible for approximately 95 per cent of the world’s supply of gemstone quality opals. The majority of Australia’s opals are found in NSW, Queensland and South Australia and come in a variety of types, including white, crystal and boulder.
The Australian Opal Exhibition is scheduled to take place in Southport on 2-3 August.
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