(IDEX Online) - Work has been suspended at one of Alrosa's biggest investment projects, the Zarya pipe, in Yakutia, eastern Russia.The 300-meter deep open pit, developed at a cost of $187m, went live just a year ago, in April 2019.Alrosa says Zarya will be put on care and maintenance from May 15 to December 31, 2020, as will the neighboring Aikhal underground mine, from May 15 to September 30.It blames a slump in demand caused by the global spread of COVID-2019 virus.It says it's closing the two pipes because they operate with lowest margins, due to the quality characteristics of their stones.The 180 miners at Zarya and 502 staff at Aikhal will be partially laid-off, transferred elsewhere, or carry on with duties at the closed pipes.Last year the pipes jointly produced 2.6 million carats.Picture shows the Zarya pipe, courtesy Alrosa