Gem Diamonds finds 172.06 ct stone at Letšeng

Africa-focused miner Gem Diamonds (LSE: GEMD) has unearthed a 172.06 ct Type II white diamond at its prolific Letšeng mine in Lesotho, just days after another major find.

The diamond, recovered on June 2, is the seventh precious stone greater than 100 carats recovered this year at the operation, the company said.

Type IIa diamonds are the most valued and collectable precious gemstones, as they contain either very little or no nitrogen atoms in their crystal structure. 

The Letšeng mine is one of the world’s 10 largest diamond operations by revenue. At 3,100 metres (10,000 feet) above sea level, it is also one of the world’s most elevated diamond mines.

Diamond miners are going through a rough patch as American and Chinese demand for diamond jewelry continues to be weak and the popularity of cheaper laboratory grown diamonds continues to rise. 

In 2015, man-made diamonds had barely made an appearance as a competitor to natural diamonds. By last year, these stones accounted for more than 10% of the global diamond jewelry market, according to industry specialist Paul Zimnisky.

The market values of small to medium diamond mining companies, including Canada’s Lucara Diamond (TSX: LUC), South Africa’s Petra Diamonds (LSE: PDL), and Gem Diamonds itself, are around $100 million or less. This is only about a third or a quarter of the price the large stones they aim to find may be worth.