Gemfields Group Ltd. Chief Executive Officer Sean Gilbertson will step down from his role after a mutual agreement with the board, marking a sudden leadership transition at a time when the gemstone miner faces a mounting crisis of plummeting ruby grades, insurgent attacks, and tens of millions of dollars in trapped tax refunds in Mozambique.
The London- and Johannesburg-listed company announced that Chief Financial Officer David Lovett will take over as interim CEO effective July 15. Non-executive chairman Bruce Cleaver, the former head of diamond giant De Beers, will take on an active role to support the management team while a formal search for a permanent successor begins.
“The board would like to thank Sean for his contribution to the company and wishes him well in his future endeavours,” Gemfields said in a statement.
The leadership shakeup comes at a critical juncture for the ruby specialist, which has been battered by a perfect storm of operational hurdles at its flagship 75%-owned Montepuez Ruby Mining (MRM) operation in Mozambique’s volatile Cabo Delgado province.
Trapped Cash and Dropping Grades
The financial strain on the southern African operation has been severely aggravated by a $28.3 million backlog in unpaid value-added tax (VAT) refunds from the Mozambican government. Gemfields revealed it has not received a single VAT reimbursement since October 2024, squeezing cash flows just as it tries to ramp up capital spending.
Compounding the cash crunch is a drastic decline in the recovery of “premium” rubies the ultra-high-quality stones that generate more than 70% of MRM’s revenue despite making up less than 5% of its total output by weight. Overall premium ruby grades plummeted by half to 0.03 carats per tonne in the first five months of this year, down from 0.06 carats per tonne in 2025. In the lucrative Mugloto domain, grades dropped to 0.02 carats per tonne.
The company blamed the low yields on an inability to access higher-grade zones due to heavy first-quarter rainfall, alongside severe commissioning bottlenecks at its new Second Processing Plant (PP2).
The $70 million PP2 facility, which began partial operations in late 2025, has suffered extensive mechanical issues, including construction defects by original equipment manufacturers that will require a full rebuild of its secondary scrubber. A replacement unit is expected to arrive on site in August. Gemfields warned that the processing delays will have a “material adverse impact on the inventory available for MRM ruby auctions for at least the remainder of this year.”
Insurgency and Illegal Mining Intrusion
Security also remains a pressing threat. Gemfields detailed a string of violent attacks by suspected insurgents in villages located within 15 to 35 kilometers of the mine concession since late April, which forced a temporary 20-hour shutdown of operations in May.
The company noted that local criminals have also begun mimicking terrorist tactics burning homes and displacing residents to loot property. Meanwhile, law enforcement struggles have led to a massive influx of illegal miners.
“These intrusions pose a considerable safety risk to MRM’s personnel, contractors and community members, and also degrade MRM’s ruby resources and recovery grades,” the company said.
An average of 700 illegal miners are now breaching the concession daily, physically degrading the resource and complicating extraction plans.
Auction Lifeline
In a rare bright spot, the company successfully trialed a new “Trade Select” auction format from June 22 to 29, which introduced sapphires alongside a broader mix of lower-quality rubies. The event generated $23.1 million, selling 92% of the lots on offer at an average price of $66.30 per carat.
The new format was designed to bridge the gap between major mixed auctions and smaller flash sales, allowing the miner to match volatile market demand more dynamically.
“While market conditions remain challenging in certain sectors of the coloured gemstone market, customer attendance was strong and bidding demonstrated continued demand,” said Adrian Banks, Gemfields product and sales managing director. “We now look forward to building on these results as preparations begin for MRM’s next mixed-quality ruby auction, presently scheduled for October.”
Despite the positive auction feedback, management faces an uphill battle. Gemfields stated it is implementing aggressive cost-management disciplines and accelerating bulk sampling to search for higher-grade pockets, while continually engaging with Mozambican authorities to unlock its trapped cash.
