Exploration company URA Holdings, which has assets in South Africa and Zambia, has announced an independent maiden Joint Ore Reserves Committee (Jorc) 2012 mineral resource estimate of 29-million carats of contained emerald at its 74%-owned Gravelotte emerald mine, in Limpopo. 

The maiden Jorc mineral resource completed by consultants ACA Howe comprises of the Cobra deposit at 1.2-million tonnes at 6.4 g/t for 19.4-million carats of contained emerald, as well as the Discovery deposit at 700 000 t at 5.7 g/t for 9.6-million carats of contained emerald. 

Further, 12 additional Jorc exploration targets totalled between 168-million carats and 344-million carats. 

"[This is] the first ever formal resource estimation for the Gravelotte emerald mine, despite its long history of production, including being one of the world's largest producers of emeralds in the 1960s.  

”[It] fully justifies the directors’ belief, at the time of acquisition, that a significant emerald resource remains unmined at the Gravelotte emerald mine. The multiple large Jorc exploration targets of between 168-million carats and 344-million carats, provide potential for significantly expanding the maiden Jorc resource," URA CEO Bernard Olivier said on November 21. 

URA said the Jorc resource was substantially larger than indicated at the time of purchase.

Mine, processing plant and infrastructure upgrades and refurbishment are currently in progress, with the goal of restarting production in 2023. Much of the historic mining infrastructure remains in place and can be upgraded for reuse, URA said.

While the company will need to acquire some new mining and processing equipment, it expects to bring Gravelotte back into initial production “relatively quickly”.

"The establishment of a maiden Jorc resource estimation of this magnitude for the Gravelotte emerald mine is a truly exceptional achievement. The combined Jorc mineral resource . . . exceeded our expectations.

“To put the numbers into perspective, if we conservatively use the average price of $9/ct as achieved by Gemfields in September for its lower-grade emeralds only, then the total contained in situ Jorc resource of 29-million carats has an estimated value of around $261-million,” URA chairperson Edward Nealon explained.

He noted that this figure excluded the additional 168-million to 344-million carats in the company’s Jorc exploration target.

“We are now focussing on unlocking this in situ value by refurbishing the mine and infrastructure and upgrading the existing processing facilities with the aim of restarting emerald mining and processing as soon as possible," Nealon said.