Liqhobong is a kimberlite diamond mine in the Maluti Mountains of northern Lesotho, in the same broad geological province as the more famous Letseng-la-Terai mine. It has been mined under various ownership arrangements since the 1990s, with the most significant modern operating period running under Firestone Diamonds plc following the construction of a 3.6 million tonne per annum treatment plant that came into commercial production in mid-2017.

Geology

The Liqhobong kimberlite complex is part of the Cretaceous-aged kimberlite cluster of northern Lesotho. The mine works the Main Pipe, an open-pit operation extracting kimberlite from a relatively low-grade but sometimes high-value resource. The grade is modest by world standards, with diamond content typically below five carats per hundred tonnes, but the mine has produced periodic large stones that materially affect quarterly revenue.

Notable production

The most prominent stone recovered from Liqhobong was a 910-carat rough diamond recovered in 2018, named the Lesotho Legend by Gem Diamonds (the producer of comparable Letseng goods, although in the case of the Lesotho Legend the stone was recovered at the Letseng mine rather than at Liqhobong itself; care is needed not to conflate the two operations). Liqhobong's own large-stone record includes diamonds in the several-hundred-carat range, with sales of these stones contributing materially to the operation's revenue in their respective quarters. The mine's tendency to recover periodic high-value goods has been a defining commercial characteristic.

Operational and financial history

The mine has had a turbulent financial history. Construction overruns, lower-than-modelled grade, and weakness in the rough diamond market contributed to an operating environment in which the mine has at various points been put under care and maintenance, refinanced, and brought back into production under modified plans. The macro-economic context of the rough diamond market between 2018 and 2024 has been challenging for low-grade producers, and Liqhobong's commercial performance has tracked the cycle.

Trade significance

For the international rough diamond trade Liqhobong's significance lies less in its bulk production than in its occasional large-stone outputs and in its role as one of the small group of Lesotho mines whose goods are recognised in the rough market as Lesotho stones. The Lesotho geological province has produced a disproportionate share of the world's largest rough diamonds in the past two decades, and Liqhobong is part of that story even though Letseng is the headline producer.