BlueRock Diamonds garnered $1.1 million from the sale of three rough stones at its August tender, achieving its highest per-carat prices all year.

The miner sold the biggest of the stones, weighing 58.6 carats, for $585,000, or $10,000 per carat, it said Tuesday. That diamond was the largest BlueRock has ever recovered from its Kareevlei mine in South Africa.

Meanwhile, the company also found buyers for a 21.6-carat stone, which fetched $268,000 — or $12,400 per carat — and a 14.3-carat diamond, which went for $236,000, or $16,500 per carat.

The values achieved by the large stones brought the miner’s sales for the August tender to $2.1 million, its highest monthly sale total to date, said BlueRock CEO Mike Houston. Its previous record for a tender was $900,000.