The update is due to be further optimised during the first semester following the completion of an updated mineral resource estimate and mine plan, however, the company said a decision to purchase the mining mobile fleet during the construction period, combined with the additional detail of basic engineering, is expected to result in moderate increases to capital and operating costs compared with the 2019 feasibility study.

The initial capital is now about US$225 million compared with $196 million in the feasibility. Infill drilling in the North Zone completed since the 2019 feasibility study added more than 200,000 ounces in the measured and indicated categories, which will boost total aggregate production over one million ounces, while maintaining the 1,250 tonne-per-day operation producing 113,000oz/y.

The update used a base case gold price of $1,500/oz compared with $1,250/oz in the feasibility, with the after tax net present value increasing to more than $300 million at a 5% discount rate compared with $241 million, although the internal rate of return has fallen from 34% to 30%.

"The gold environment has since improved significantly, and offsets increases to capex due to advancing engineering and de-risking of the project. Looking forward into 2021, we intend to update the Cerro Blanco resource estimate and mine plan in the first half of the year," said Blusetone Resources president Darren Klinck.

Bluestone began the year with a cash balance of $50 million.

Shares in Bluestone Resources are trading at C$1.90, valuing the company at $273 million.