Canadian mining company Lucara Diamond on Monday, May 9 announced the sale of a huge 813-carat diamond for a record $63 million (55 million euros), according to AFP.

The sale of the massive "Constellation" diamond was "the highest price ever achieved for a rough diamond, breaking all records," CEO William Lamb said in a statement.

The name of the buyer for the gem, which was discovered in Botswana, was not divulged, nor the conditions of the sale overseen by Nemesis International.

Lucara Diamond said it retained a 10 percent interest in the net profit from the sale of the polished diamonds that the stone will yield.

The record sale figure is unlikely to last very long. Lucara is preparing to auction an even larger 1,109-carat diamond at Sotheby's in London on June 29.

Both diamonds are from Lucara’s Karowe open pit mine in Botswana, which is gaining a reputation for spectacular stones.

Lucara shares had soared by 8.58 percent by mid-afternoon on the Stockholm market. The main shareholder in the Canadian company is the Swedish Lundin family.