Workers at the Beta Hunt mine near the small town of Kambalda, 630 kilometres east of Perth, have brought more than $15 million worth of gold specimens to the surface in just four days.
The gold-encrusted rocks were found about 500 metres below the surface in an area just three metres wide and three metres high.
The largest specimen weighs in at 90 kilograms and took three men to lift it onto the back of a ute.
The quartz rock is covered in an estimated 2,300 ounces of gold worth about $3.8 million at today’s gold price.
Another 60kg specimen is estimated to contain 1,600 ounces, or about $2.6 million in gold.
Senior geologist Zaf Thanos said in most mines around the world it is only possible to see gold through a magnifying glass.
“You might go your whole life and you’ll never see anything like it. It’s definitely a once-in-a-lifetime discovery,” he said.
The rich cluster of high-grade gold has so far produced more than 9,000 ounces.
Kambalda miner Henry Dole is credited with the discovery, describing it as hitting the “mother lode”.
Mr Dole had drilled holes into the wall of the mine and planted explosives which were fired once he was safely on the surface.
A handful of gold rocks could be worth several thousand dollars, so security has been beefed up in the days since the find.
Armed guards have been transporting the gold to a secure vault.
Workers are under constant video surveillance and the area of the mine where the gold was found has been fenced off and padlocked.
The irony is that Beta Hunt has been mined for nickel, which is a key ingredient in stainless steel, since the 1970s, and gold has always played second fiddle.
There are stories among the workforce dating back to the early days of the mine which suggest similar bonanza finds may have been made in the past but were not considered significant at the time because of low gold prices.
There are also tales that workers in those days would bury bags of gold rocks in the event the commodity came back stronger.