Botswana’s sale of diamonds increased by 4.7% last year, officials from Debswana said Monday, a joint venture of diamond industry giant De Beers and the Botswana government.

Debswana officials attributed the increase to greater efficiency in mining techniques, The Associated Press reports.

“It was a surprisingly good year,” said. Debswana has also launched work at a new mine in hopes of increasing production even further and lessening dependence on existing mines, the AP reports. Despite last year’s success, Louis Nchindo, Debswana’s managing director, said there were concerns about the coming year because of the possible war in Iraq and the international economic instability it could provoke.

Debswana is the world’s largest source of rough diamonds.

JCK