(IDEX) - Alrosa's monthly figures reveal the full impact of COVID-19, with April sales of rough and polished plunging to just $15.6m.That's a fall for the state-owned Russian miner of 96 per cent on $405m sales in January, before coronavirus lockdowns and travel restrictions came into force. Sales for the world's largest diamond producer by volume in 2019 were $3.3bn.Alrosa sounded a note of optimism, is predicting the possible return of increased demand as soon as July."The challenges and restrictions faced by the market and affecting both operations and demand are of a temporary nature," said deputy CEO Evgeny Agureev."We deal with a rare and limited natural resource, and consumers attach a high emotional value to natural diamonds. "Like many other market players, we expect to see an upward trend in demand for diamonds as early as in the beginning of Q3."He said the company had offered clients an option to buy April's allocation of rough diamonds at a later date.Alrosa has halted production at its two least profitable mines, in Yakutia, eastern Russia, and temporarily laid off 1,000 workers as it suspends it cutting and polishing operations.Pic of rough diamonds courtesy Alrosa