(IDEX Online) - Alrosa bought more diamonds this week from Gokhran, the Russian state repository of precious gems and metals, as it sought to replenish its dwindling inventory.It said it purchased 80 per cent of the rough stones offered at auction on Tuesday but did not disclose the price it paid. It was previously reported that Gokhran would be offering 768,600 carats, worth about $19m, at its September auction.In July Alrosa bought 70 per cent of the 1.02m carats, sold by Gokhran for a total of $139.2m, according to the Interfax news agency.The miner has been warning of "a long period of supply deficit" in the rough market as demand remains high, mid-stream stocks run low and miners' inventories hit rock bottom. "By participating in the Gokhran auction, we were able to partially compensate the diamonds shortage amid strong demand from clients," said Evgeny Agureev, Alrosa's deputy CEO.Pic courtesy Alrosa