Huge encrusted rocks have been discovered in Australia

The miners in western Australia said they discovered two huge gold-encrusted rocks each estimated at millions of dollars.

The largest specimen, weighing 95 kg (210 lb), contained more than 2,400 ounces of gold, said Canadian miner RNC Minerals.

The company said it had mined gold worth about 15 million Canadian dollars ($ 9 million) in a mine near Kalgoorlie last week.

A mining engineer described the discoveries as "extremely rare".

"People are still recording nuggets in the gold fields, but in general they are less than several ounces," said Professor Sam Spearing, director of Curtin University's Western Australia School of Mines.

The mining company has valued the largest rock at about C $ 4 million. He said the second largest – a 63 kg specimen with an estimated 1,600 ounces of gold – was worth $ 2.6 million Canadian.

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The rocks were also quartz, the company said.

Miners in Australia often extract as little as 2 g of gold per ton of rock, Prof. Spearing told the BBC. RNC Minerals reported extracting 2,200 g per tonne.

"Very, very rarely, we see results at this level.It is an extremely rare and very exciting discovery," said Professor Spearing.

He said that gold particles were often too small to be visible to the human eye.

The Beta Hunt mine was essentially operating as a nickel operation until last week's discovery.

The company had targeted the gold vein, located 500 m underground, after finding traces of gold closer to the surface in June.

RNC Minerals General Manager Mark Selby said the biggest rocks would be auctioned off as collectibles.