Lucara pulls rare 36.92-carat blue diamond from Karowe stockpile

Lucara Diamond Corp recovered a 36.92-carat blue diamond from its Karowe mine in Botswana in March 2026, classifying the stone as a high-quality Type IIb diamond — a rare category whose blue colour comes from trace boron and which commands exceptional value in the market.

The diamond was recovered by processing historic stockpile material using X-ray transmission sorting technology, the same method that has allowed Karowe to keep extracting value from previously mined, lower-grade ore. Lucara said it was only the second special blue diamond found at Karowe since the mine began operating, following a 9.74-carat blue stone discovered in 2019 — underlining just how rare stones of this colour and quality are, even at a mine as prolific as Karowe.

A run of large stones

The blue diamond formed part of a broader run of good fortune at Karowe: chief executive William Lamb said the company had recovered five stones exceeding 100 carats from processed stockpile ore since the start of 2026 alone, a pace that reinforced the value locked up in material many mines would treat as low-priority waste. Lamb said the latest find "reinforces the special nature of this asset," pointing to the stockpiles as an increasingly important source of mill feed alongside fresh open-pit ore.

Coming after a tough year

The discovery landed just weeks after Lucara reported that 2025 revenue had fallen 22% to $159.7 million and profit had dropped 35% to $26.1 million, partly blamed on a temporary shortage of the very largest stones. A find of this calibre offered some reassurance to investors that Karowe's exceptional geology had not gone quiet, even if the timing and size of individual discoveries remain inherently unpredictable.

Why blue diamonds command such interest

Blue diamonds are among the rarest and most sought-after categories in the market, prized by collectors and high-end jewellery houses precisely because laboratory-grown alternatives, while increasingly common in white diamonds, have struggled to replicate the specific conditions that produce natural blue colouration at scale and quality. For Karowe, a mine already famous for giant white stones like the 1,109-carat Lesedi La Rona, a genuine blue diamond discovery added a new dimension to its reputation as one of the world's most remarkable diamond deposits.

Sources

• Rapaport: Lucara's Karowe Mine Turns Up 37ct. Blue Diamond, 17 Mar 2026

Photo: A polished diamond; Lucara's Karowe mine in Botswana recovered a rare 36.92-carat blue diamond. Pavel.Somov, Wikimedia Commons, CC BY 4.0.