British-based mining firm Gem Diamonds has opened the Ghaghoo diamond mine in Botswana.

Ghaghoo is the first underground diamond mine in the country and is estimated to hold 20.53 million carats worth $4.9bn.

Gem Diamonds CEO Clifford Elphick said: "This is a significant step forward for Gem Diamonds as a company, as we add another mine to our portfolio of producing assets.

"The potential of this ore body and the economic benefits to shareholders, employees and the Botswana nation will soon become evident."

During the initial studies, the company recovered 2,400ct that are sold in the range of $260 to $270 a carat. The first phase of diamond production, which is anticipated from 2015, will be at a rate of 250,000ct to 300,000ct a year.

"The mine and our investment to-date demonstrates our commitment to the country and to the people of Botswana."

Gem Diamonds will employ around 250 workers during the first phase of production, where it aims to confirm the grade, diamond price and the recovery processes, including usage of autonomous milling.

The company plans to further develop the mine based on the results of phase one.

Gem Diamonds has carried out number of studies and assessments related to the environment, local communities and broader social impacts of the Ghaghoo mine to ensure that the mine operates under international standards.

Elphick said: "We believe that our steadfast approach and commitment to being an excellent corporate citizen, and working to ensure we operate in an environmentally and socially responsible manner is key in determining the long-term success of the Ghaghoo mine.

"The mine and our investment to-date demonstrates our commitment to the country and to the people of Botswana. We see considerable opportunities in playing an important role in the country’s future and bringing jobs and economic opportunities to the surrounding communities."

Image: The Ghaghoo mine is located in the south-east portion of the Central Kalahari Game Reserve in Botswana. Photo: courtesy of Gem Diamonds.