De Beers closing another diamond mine, this time in Botswana

Debswana's Orapa Mine.

Botswana's diamond mining giant, Debswana, is closing its Damtshaa mine, and will scale down production at Orapa No.1 operation for the next three years as it battles a continued downturn in the global diamond market, local paper Southern Times reports.

The company - a 50/50 joint venture between De Beers and the Botswana Government - had forecast production of 22 million carats for 2015, but in September the company revised the figure down to 21 million.

The news comes on the heels of De Beers sale of its Kimberley Mines in South Africa and its decision to close Snap Lake in Canada.

The expected closures will leave about 1,000 workers jobless in a country where diamonds make up more than 70% of its total exports, and nearly 25% of its gross domestic product.

The country's diamond mines, however, are becoming bigger and deeper and costs are rising. That situation, paired with dropping prices for the precious rocks, has made it challenging for miners to remain competitive.

Botswana, which last year was overtaken by Russia as the world's top producer, is also grappling with power and water shortages.

Besides diamonds, Botswana also produces nickel, copper, coal and iron ore.