(IDEX Online) - Just three countries - Russia, Australia and the Democratic Republic of Congo - jointly produced almost 80 per cent of the world's diamonds last year.Russia was the single biggest diamond producer. It mined 19m carats - just over 35 per cent - according to new data analyzed by the finance website Finbold.Australia and Congo tied for second place, both producing a little over 22 per cent of total production, or 12m carats. The three countries jointly produced 79.62 per cent of the world's diamonds.Botswana trailed in fourth place with nine per cent, or 5m carats, but has the second biggest reserves - 310m carats, according to estimates by the United States Geological Survey (USGS).Russia has by far the biggest reserves, estimated at 650m carats, or 34 years at current rates of consumption.Pic shows rough diamonds mined by Russia's Alrosa