Diamond miner Lucara Diamond Corp’s revenue for the second quarter ended June 30 decreased by 6% year-on-year to $41-million, largely owing to lower carat sales through tender and a lower average dollar-per-carat price from diamonds weighing less than 10.8 c.

The period’s revenue included the sale of the 2 488 ct Motswedi, while the prior comparable quarter’s revenue included the sale of the 1 094 ct Seriti.

Operating cost decreased by 11% to $23.76/t processed, below full-year guidance range of $27.50/t to $31/t processed, largely owing to an increase in tonnes processed during the quarter and partially offset by higher electricity and fuel costs.

A total of 90 082 ct were recovered in the period, with 83 109 ct from direct ore feed from the pit and run-of-mine stockpiles, at a recovered grade of 10.9 carats per hundred tonnes (cpht), and an additional 6 973 ct recovered from the processing of historical recovery tailings.

There were 176 special diamonds – those weighing more than 10.8 ct each – recovered in the quarter.

Lucara maintains its full-year outlook, including its revenue guidance which remains unchanged at $100-million to $130-million.

Openpit mining continued through the period and remains on track to conclude in the fourth quarter, consistent with the company’s prior outlook.

Following depletion of the open pit, it will continue processing run-of-mine stockpiles, comprising ore previously mined but not yet processed.

Subsequent to quarter-end, Lucara recovered a 1 303 ct Type IIa diamond in July, the company’s tenth diamond in excess of 1 000 ct since operations started.

Also in July, the 15-person auxiliary winder and the 105-person man and material winder on the production shaft were licensed by the Botswana Department of Mines, a significant milestone in the shaft sinking and equipping programme for the Karowe Underground Project (UGP).

“The quality of the Karowe resource is undeniable, as reaffirmed by the recovery of our tenth diamond weighing more than 1 000 ct, a stunning D-colour, Type IIa white diamond,” CEO and president William Lamb acclaims.

“During the second quarter, Lucara continued to execute against our strategic priorities while maintaining our focus on safe, disciplined operations at Karowe. With openpit mining substantially complete and the UGP advancing well, we continue to make meaningful progress toward the mine’s next phase of production and long-term value creation.

“The successful completion of our financing strategy earlier this year has strengthened our financial position, allowing us to continue advancing the UGP while maintaining operational flexibility,” Lamb informs.

“As we move through the second half of 2026, our priorities remain firmly focused on the safe and timely delivery of the UGP. The UGP is expected to extend access to one of the world’s most exceptional diamond orebodies, supporting Lucara’s long-term ability to recover rare, high-value diamonds and create sustainable value for all stakeholders,” he adds.

The UGP is designed to access the highest-value portion of the Karowe orebody, with initial planned underground carat production predominantly from EM/PK(S)3.

The UGP is expected to extend the mine life to 2038.

On January 30, Lucara announced an update to the UGP schedule and budget. Full-scale production from the UGP is anticipated in the first half of 2028, with a total estimated cost at completion of $779.2-million (including contingency).

At period-end, remaining costs to complete the UGP, including contingency, were $275.9-million. Committed, not yet incurred, UGP costs were $99.8-million.

Lucara says the UGP has progressed well, reflected by reaching the bottom of the 776 m production shaft and the 729 m ventilation shaft last year, significantly derisking the project as shaft sinking activities were concluded.

In July, the production shaft auxiliary and man and material winders were licensed by the Botswana Department of Mines, marking a key milestone in shaft sinking activities, as alluded to.

However, construction of the headframe steel took longer than scheduled owing to late and out-of-sequence steel deliveries and the requirement for on-site steel rework, leading to an about six-week delay.

This delayed the mobilisation of the lateral development contractor, Group R Mining, which is now scheduled to start underground mining activities this month.

To mitigate the impact, additional lateral development was completed during the period, creating additional headings from which Group R can start mining and supporting an accelerated ramp-up of lateral development activities.

The licensing of the main production shaft on July 17 also enabled the slinging of major lateral development equipment underground in preparation for the start of mining activities.

Lucara says it has maintained its overall project schedule and project costs.

The ventilation shaft continued advancing lateral development during the period, primarily at the 310-level. About 410 m of lateral development was advanced in the quarter, bringing project-to-date lateral development to 1 655 m at period end.

The UGP’s ongoing hydrogeological monitoring programme continued throughout the quarter.