Spring Valley Project

Reserves and Resources

Mineral Reserves (effective date of October 31, 2025)

Notes:

• The Mineral Reserve estimate was prepared in accordance with the 2014 CIM Definition Standards.
• The Mineral Reserve estimate is contained within pit designs using Indicated Mineral Resources only and a gold price of $1,800/oz.
• The Mineral Reserve estimate is based on an ore cut-off grade of 0.003 oz/ton gold.
• Excludes contained gold in overliner material.
• ROM design ore recovery: 79% of oxide contained; 70% of transition contained; 56% of sulfide contained. Crushed design ore recovery: 88% of oxide contained; 80% of transition contained; 74% of sulfide contained.
• Mining costs: Average base mining cost: $1.53/ton Ore; $1.36/ton Waste Rock; $0.98/ton Alluvium; mining cost adjustment factor: $0.048/ton per 25 ft bench.
• Process costs: $2.65/ton ROM ore; $3.32/ton crushed ore; refining costs: $0.75/oz; general and administrative (G&A) costs: $0.80/ton total ore; transport costs $0.63/oz gold; $1.43/ton autonomous mining costs.
• The Mineral Reserve estimate is reported within a pit design that uses geotechnical parameters developed by WSP, where the recommended pit slope angles range from 34° to 47°.
• Unplanned dilution was estimated and included in the reserves.
• There are no known legal political, or environmental risks that could materially affect the potential development of the Mineral Reserve estimate.
• Royalties were applied to the Spring Valley Mineral Reserves with an average royalty burden of 4.3% of net smelter return (NSR). The individual royalties are between 1% and 7% as described above.

Mineral Resources (effective date of October 31, 2025)

Notes:

• ton=short tons, oz/ton=ounces per short ton, koz= kilo troy ounce.
• There is no known depletion by mining within the model area.
• Estimation is by LMIK for ZONECODES 100, 200, and 300. ZONECODE 350 was estimated using ROK due to limited data.
• Near surface Mineral Resources are constrained by a nominal optimized pit shell.
• Metal prices of $2,200/oz gold.
• Pit angles vary from 32° in alluvium to 43°.
• Crusher process recoveries of 88.7%, 87.4%, and 74.9% for oxide, transitional, and sulfide respectively, and ROM process recoveries of 80.1%, 71.10%, and 62.5% for oxide, transitional, and sulfide respectively.
• Mining costs $1.43/ton autonomous, processing costs $2.90/ton (ROM), $4.40/ton (crusher), G&A costs of $0.79/ton, selling costs of $1.42/oz gold.
• Royalties between 1% and 7%, payable 99.75%. Solidus owns 1% of the 7% royalty, and thus in the locations where the 7% royalty applies, the royalty value is effectively 6%.
• The assumed mining scenario is for bulk open pit mining on a 25 ft bench or flitch with limited selectivity and heap leach processing.
• Cut-off grade applied to the pit constrained Mineral Resources is 0.003 oz/ton gold.
• Drilling results up to 3 February 2023.
• Rounding of some figures may lead to minor discrepancies in totals.
• Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
• CIM Definition Standards (2014) were used for reporting. 
• Measured and Indicated Mineral Resources are exclusive of Mineral Reserves.