An underground mine in WA’s Goldfields has produced what its owner believes are two of the biggest gold specimens in recorded history in what has been described as a “once-in-a-lifetime” discovery.

Since last weekend, RNC Minerals has been tallying the bonanza haul from a single cut of rock blasted about 500m underground at the 45-year-old Beta Hunt gold mine near Kambalda, 600km east of Perth and 50km south of Kalgoorlie-Boulder.

The biggest of the stones came in at 90kg and is estimated by the company to contain about 2300 ounces of gold, a total that at current prices would be worth about $3.8 million.

The second-biggest piece was not far shy at 60kg, with an estimated 1600oz lodged within the quartz specimen, valued at about $2.7 million. And there’s more where that came from.

Early estimates from RNC have put the total take of coarse gold from the cut at more than 9000oz, or more than $15 million worth.

RNC Minerals mined just 13,320oz at Beta Hunt in the whole of the June quarter.

Airleg driller Henry Dole has been credited with uncovering the astonishing find.

The Kambalda resident has been in the profession for 16 years and says he has never seen anything like it.

“I’ve seen it in veins in the face but nothing like this — this was just everywhere,” he said.

“As I was drilling it, you could see the gold shavings coming out of all the holes and I thought ‘there’s something here’.

“And then after we fired it and I came in the next day and washed it all down, it was just everywhere.

“It was unbelievable and I’ve never seen it before in my life.”

Camera Icon Geologist Lachlan Kenna, Henry Dole, foreman Warren Edwards and senior geologist Zaf Thanos with the 90kg gold specimen. Credit: Kelsey Reid

When the 90kg behemoth was found, it took three people to lift it on to a utility vehicle so it could be hauled to surface.

“That was virtually the next day after we fired it, we walked in there and you couldn’t miss it ... especially when you hit it with water, it just stuck out,” Mr Dole said.

“We shouldn’t have really lifted it, we should have used the bogger but we got it on the back of the ute.”

The fact Canadian owner RNC has the mine up for sale adds to the intrigue of the discovery.

RNC’s Toronto-based chief executive Mark Selby said the gold rush-style find was uncommon in the modern day, at a time when miners are producing gold at lower and lower grades. “This is one of those once-in-a-lifetime moments where people find 2300oz and 1600oz chunks of gold,” he said.

“It’s generally an exciting moment, and given it’s been a tough slug for us at the mine, to make this kind of discovery just reinforces that we always knew this mine had potential.

“We’re going into a sales process to put it into hands to raise the capital to do this exploration, to find these areas we know are there, and hopefully retain some equity interest.

“But this discovery shows Beta Hunt has the potential to be a very large gold mine going forward.”

Most gold in WA is crushed and processed into gold bars before being sold to the Perth Mint, but it is understood the specimens from Beta Hunt could go to auction, where they may garner a premium from gold collectors.

It is not the first time Beta Hunt, which has been mined for nickel since it opened in 1973, has produced high-grade finds in its renaissance as a gold operation.

RNC’s Australian subsidiary Salt Lake Mining uncovered a museum-grade specimen from the Hand of Faith area at Beta Hunt two years ago, and just two months ago RNC pulled 1500oz of coarse gold from an area near last week’s find.

Salt Lake geology manager John Vinar said it was special to see gold in that form.

“I’m really lucky to be seeing this — it’s a rarity,” he said. “I don’t know of many other places that are able to deliver this type of material. We’ll target our drilling to see whether we can unearth more.

“We thought the HOF was the best thing but it only delivered about 1000oz, whereas this has eclipsed everything, so it’s beyond our wildest dreams to see that amount of gold come out.”

WA’s Goldfields has been home to major nuggets, including the famous Golden Eagle, which weighed 1186oz and was found in 1931 at Larkinville, just 40km south-west of Beta Hunt.