(IDEX Online) - Alrosa is to widen its diamond exploration program in Zimbabwe. It has increased its stake from 25 to 35 the number of diamond prospecting special grants it holds in the country.The Russian state-owned miner announced a joint venture in December 2019 with the Zimbabwe Consolidated Diamond Company (ZCDC) to jointly explore for gems. Alrosa holds 70 per cent, ZCDC holds 30 per cent."Alrosa is optimistic about the prospects of the diamond industry in Zimbabwe," said the company in a statement.Initial exploration will take place in mountainous Chimanimani (pictured), in south-eastern Zimbabwe, close to the border with Mozambique, an area known to attract Russian prospectors and illegal miners.