Diamond miner De Beers has reported an 11% year-on-year decrease in rough diamond production to 6.8-million carats for the quarter ended September 30, primarily driven by planned plant maintenance at Orapa, in Botswana, and a slowdown at Venetia, in South Africa, ahead of a planned two-year production pause.

De Beers notes that production in Botswana decreased to 4.8-million carats, as a result of the planned plant maintenance at Orapa.

Further, the company warns that planned plant maintenance at Jwaneng in the fourth quarter is expected to substantially decrease production levels, compared with the third quarter.

In Namibia, production remained stable at 500 000 ct.

In South Africa, production decreased to 400 000 ct, as Venetia ramped down production and processing ahead of its production pause. While activities to support the production pause will continue into early 2027, the company says no further carat production is expected this year.

Additionally, in Canada, production increased to 1.1-million carats, owing to the planned processing of higher-grade ore at Gahcho Kué.

De Beers points out that it has assumed full ownership of the Gahcho Kué mine, in Canada, with effect from October 16, following the enforcement of security over Mountain Province Diamonds' 49% interest in the joint operation.

As a result, De Beers will in future report 100% of Gahcho Kué mine production and sales rather than 51%. While this does not impact global supply, the company says this will result in an increase in De Beers' reported attributable production.

DIAMOND MARKET

De Beers states that rough diamond trading conditions showed signs of stability during the third quarter, reflecting a more balanced supply-demand landscape and improved consumer demand across the US and India.

Synthetic lab-grown diamonds, however, continued to affect demand for lower-value natural diamonds, adding pressure in more price-sensitive categories.

The company notes that the year-to-date consolidated average realised price declined by 37% to $97/ct, as a result of an 18% decrease in the average rough price index and the return to a more balanced sales mix – a higher proportion of higher-value goods were sold in the third quarter of 2025.

Rough diamond sales in the third quarter totalled 9.8-million carats (8.7-million carats on a consolidated basis) from two sights, generating consolidated rough diamond sales revenue of $731-million.

This compares with two sights in the third quarter of 2025, during which 5.7-million carats (4.6-million carats on a consolidated basis) were sold, generating $700-million of consolidated rough diamond sales revenue.

De Beers has revised its production guidance for this year to between 25-million and 28-million carats (100% basis) from 21-million to 26-million carats previously, reflecting De Beers assuming full ownership of the Gahcho Kué mine.

De Beers says it continues to monitor rough diamond trading conditions to align output with prevailing demand.

Unit cost guidance for the year is revised to about $70/ct from about $80/ct previously, reflecting the increased contribution from Gahcho Kué, the impact of the Venetia production pause and ongoing cost control across all operations.