The new year started off with a bang for two of the world's most famous diamond mines. On January 9, Gem Diamonds unearthed a high-quality 295-carat stone at its prolific Letšeng mine in Lesotho. Only one day later, Lucara Diamond Corp. showed off a 166-carat sparkler from its Karowe mine in Botswana.

Both mining companies described their finds as white, Type IIa stones, which are colorless and chemically pure with no traces of nitrogen impurities.

Situated two miles above sea level in the tiny, landlocked Kingdom of Lesotho, the twin Letšeng diamond mines churn out some of the largest and highest-value diamonds in the world. In fact, the Letšeng site generates the highest average dollar-per-carat of any kimberlite diamond mine in the world.

Among the country’s highest-profile rough diamonds are the Lesotho Legend (910 carats), Lesotho Promise (603 carats), Letšeng Star (550 carats), Lesotho Legacy (493 carats), Light of Letšeng (478 carats), Letšeng Icon (439 carats), Letšeng Princess (367 carats), Letšeng Dynasty (357 carats) and the Letšeng Destiny (314 carats).

The most recent find signals an encouraging start to 2024. The Letšeng mine is hoping to score some bigger pay days this year because the number of 100-carat-plus diamonds generated by the mine has been declining in recent years. After unearthing 16 super-large diamonds in 2020 and six in 2021, the number decreased to four in both 2022 and 2023, according to rapaport.com.

The recovery of 100-carat-plus gems is essential to the financial health of Gem Diamonds because these high-value diamonds reportedly account for 70% and 80% of the company's revenue each year.

In Botswana, the 166-carat diamond sourced from Karowe's highly productive South Lobe represented the mine's 328th stone larger than 100 carats since it commenced operations in 2012.

According to Wikipedia's list of the largest rough diamonds ever found, seven of the top 21 have come from the Karowe Mine. The largest Karowe finds include Sewelô (1,758 carats), Unnamed (1,174 carats), Lesedi La Rona (1,109 carats) and Unnamed (998 carats).

The Karowe Mine had been expected to cease operations in 2025, but an underground expansion at the cost of $683 million will extend its productive lifespan until at least 2040.

Credits: Letšeng diamond image courtesy of Gem Diamonds. Karowe diamond image courtesy of Lucara Diamond Corp.