(IDEX Online) - Bluerock's largest ever rough gem from its Kareevlei mine in South Africa has sold for $585,000.The 58.6-carat stone is a D-color makeable (pictured) - colorless but with spotted black sulphide intrusions.The London-based AIM-listed miner also sold a 21.6-carat stone for $268,000. A 14.3-carat stone fetched $236,000 - setting a company record this year at $16,500 per carat.The three stones, all recovered this, sold for $1.1m altogether, boosting the company's total sales for its August tender to $2.1m, far in excess of its previous monthly high of approximately $900,000.The average price per carat for the whole parcel was about $800, said executive chairman Mike Houston.