Polymetal International said it had upgraded the mineral resource estimate at its Prognoz silver deposit in Russia.
The fresh estimate amounted to 256m ounces of silver equivalent at 789 grams per tonne.
‘In-fill drilling results exceeded our expectations and strengthened our belief that Prognoz may succeed Dukat as one of the largest primary silver deposits in the world,’ chief executive Vitaly Nesis said.
Pure silver contained decreased by 19% to 237m ounces, but the average silver grade increased by 25% to 731 grams per tonne and the average vein width increased by 15% to 2.2 metres.
Polymetal said it intended to conduct more drilling at the site in 2019, with the results of a pre-feasibility study expected in the first half of 2020.