Botswana exported $95.9 million worth of rough and polished diamonds in August, the lowest level of exports since August 2009, at the depth of the global economic crisis.



The sharp decline is an 81.9% year-over-year drop and a 63.2% decline, compared to July, based on figures published by the Bank of Botswana.



De Beers, the premier diamond miner in the country, slowed mining and decreased its supply of rough diamonds in response to a depressed diamond market.



Diamonds, mainly rough, are Botswana's leading source of income. It is not only the largest diamond producing country by value, it also has a budding diamond-polishing sector.



According to the bank, Botswana exported $2.34 billion worth of rough and polished diamonds in the first eight months of 2012.