Gem Diamonds finds 172-carat stone at Letšeng

The 172.06 ct Type II white diamond recovered at the Letšeng mine. (Image courtesy of Gem Diamonds.)

Africa-focused miner Gem Diamonds (LON: 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 2nd, is the seventh greater than 100-carat precious stone 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 ten 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 US and Chinese demand for diamond jewellery 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 (TSX: LUC), South Africa’s Petra (LON: PDL), and Gem Diamonds itself, are around $100 million or less. This is only about a third or a fourth of the price the large stones they aim to find may be worth.