A Canadian mining firm says it has unearthed the largest diamond ever found in North America.
Dominion Diamond Mines says the 552-carat yellow diamond was found at its Diavik mine in the Northwest Territories.
It says the stone ``far surpasses'' the previous record-holder, known as the Diavik Foxfire, which was found at the same mine in 2015.
Dominion, which owns 40 per cent of the Diavik mine, says in a statement that the find ``is completely unexpected for this part of the world and marks a true milestone for diamond mining in North America.''
It says the gem will not be sold in its rough form, and the company will find a partner in the coming weeks to cut and polish the stone.
The company says it's too early to determine a value for the giant diamond, but the Diavik Foxfire eventually yielded two stones that sold for US$1.3 million.