A massive rough pink diamond has been unearthed in Rio Tinto’s Argyle diamond mine in Western Australia, CNN reports.

At 12.76 carats, the remarkable find is said to be the largest stone ever discovered in the country and is expected to sell for up to $10.6 million, according to theHerald Sun.

Named the Argyle Pink Jubilee, the gem is similar in color to the 24-carat Williamson Pink given to Britain’s Queen Elizabeth II as a wedding gift, explains theTelegraph.

“A diamond of this caliber is unprecedented — it has taken 26 years of Argyle production to unearth this stone, and we may never see one like this again,” Argyle Pink Diamonds Manager Josephine Johnson said in a statement.

The gem is being cut and polished into a single stone over a 10 day period and will be up for auction later in the year, Rio Tinto said.

In November 2010, Sotheby’s Geneva office sold a 24.78-carat fancy intense pink diamond for more than $46 million, which set the world’s auction record for any diamond and jewel at $1.86 million per carat.

More than 90 percent of the world’s pink diamonds come from the Argyle mine.