The Jwaneng mine, the richest in the world, recently celebrated its 25 years in Botswana. The mine holds resources that produce up to 15 million carats a year, and is especially popular for its blue diamonds.

"When these gemstones are cut and polished, they produce eight million pieces of jewellery in a year. This means over the last 25 years Jwaneng mine's diamonds have been worn by over 100 million customers all over the world", said Gareth Penny, chief executive of De Beers.

The Jwaneng mine contributes to 70% of the annual earnings of all the four Debswana diamond mines, a 50/50 partnership between the government of Botswana and De Beers. It is scheduled to move to underground mining in 2012, and according to Penny, the increased costs of diamond mining pose a problem in Botswana.