(IDEX Online) - The Damtshaa mine, in Botswana, will reportedly close for three years as COVID-19 disruption and the consequent weak demand renders it unviable.The Debswana-operated deposit produces around 500,000-carats annually of lower-value diamonds - just 2.5 per cent of the country's total output.Joseph Tsimako, president of the Botswana Mine Workers Union told the Reuters news agency of the closure, to take effect next year, although Debswana has not so far made any comment.A plant at the nearby Orapa Mine, which processes ore from Damtshaa, will also close for an indefinite period, said Mr Tsimako, with the combined loss of up to 500 jobs.Damtshaa, which opened in 2003, closed for two years from 2015 to 2017 when rough demand slumped. It is run by Debswana, a partnership between De Beers and the Botswana government."The mine produces lower quality diamonds which makes it expensive to dig during this period when the market is depressed," Mr Tsimako told Reuters.Pic shows processing plant at Orapa Mine