BlueRock Diamonds (LSE: BRD) jumped more than 16% today after the miner announced it had found a 58.6-carat diamond at its Kareevlei mine, in Kimberley, South Africa.
The stone is the largest diamond found to date at Kareevlei.
"The final value dependent upon the buyer's confidence of what cut stones can be recovered," the company's executive chairman, Mike Houston, stated in a press release.
The discovery comes only a week after Bluerock recovered a 21.6-carat diamond from the same mine.
"This is a very important discovery for BlueRock as it supports the 'size frequency distribution charts' that indicate our pipes will deliver large high value diamonds," Houston added.
The executive also noted that the "run of mine" parcel of diamonds recovered this year have secured values of over US$400 per carat.
The two diamonds will be sold at the end of the month, BlueRock said.
Shares in BlueRock climbed to ?47.22 in early morning trading on the announcement and were still up 10.6% at ?44.8 by 2:30 p.m. GMT, leaving the miner with a market capitalization of ?5.72 million (about US$7.9 million).
The company, which updates the market when it recovers stones valued at over US$50,000, fetched US$163,000 in January for a 14.8 carat diamond.