Gem Diamonds Limited operates diamond mines. The company's flagship project is the Letšeng mine located in the located in the Maluti Mountains of Lesotho. It also manufactures, sells, and markets rough and polished diamonds. In addition, the company provides technical, financial, and management consultancy services. It operates in Lesotho, Belgium, British Virgin Islands, Republic of South Africa, Cyprus, and the United Kingdom. The company was incorporated in 2005 and is headquartered in London, the United Kingdom.