Mineral Reserves and Resources

Consolidated Estimated Mineral Resources

MINERAL RESOURCES – Inclusive of Mineral Reserves												CONTAINED METAL
	Category	kt	TCu %	SCu %	Zn %	Pb %	Mo %	Ag g/t	Au g/t	Fe %	Co ppm	Cu kt	Zn kt	Pb kt	Mo kt	Ag koz	Au koz	Fe³ mt	Co³ kt
Pinto Valley¹ 31-Dec-2025	Measured	641,584	0.32				0.006					2,050			39
	Indicated	698,102	0.26				0.005					1,847			36
	M&I	1,339,686	0.29				0.005					3,897			75
	Inferred	138,802	0.28				0.006					390			7
Cozamin² 31-Dec-2025	Measured	443	1.31		1.14	0.36		52				6	5	2		744
	Indicated	17,068	1.29		1.23	0.46		44				220	209	78		23,918
	M&I	17,511	1.29		1.22	0.45		44				226	214	79		24,662
	Inferred	13,547	0.72		1.84	0.76		39				97	249	102		16,975
Santo Domingo³ 31-Mar-2024	Measured	134,000	0.51						0.07	26.9		679					293	36
	Indicated	413,000	0.25						0.03	n/a		1,025					449	95
	M&I	547,000	0.31						0.04	n/a		1,704					742	131
	Inferred	230,000	0.21						0.03	n/a		477					200	46
Mantoverde⁴ Sulphides (Flotation)	Measured	174,942	0.56						0.10		178	988					588		31
	Indicated	320,165	0.41						0.10		115	1,308					1,035		37
	M&I	495,107	0.46							0.10		137	2,296					1,623		68
	Inferred	550,089	0.37						0.08		33	2,035					1,416		18
Sulphides Mixed (Flotation)	Measured	33,048	0.44						0.09		76	145					92		3
	Indicated	35,335	0.35						0.08		90	124					96		3
	M&I	68,383	0.39						0.08		83	269					188		6
	Inferred	19,801	0.29						0.07		14	57					42		1
Oxides + Mixed (Heap Leach)	Measured	87,076	0.43	0.33								283
	Indicated	53,909	0.39	0.30								161
	M&I	140,985	0.41	0.32								444
	Inferred	8,111	0.38	0.28								23
Oxides + Mixed (Dump Leach) 31-Dec-2025	Measured	144,629	0.22	0.15								210
	Indicated	140,518	0.21	0.14								199
	M&I	285,147	0.22	0.15								409
	Inferred	59,985	0.22	0.13								80
Mantos Blancos⁵ Sulphides + Mixed (Flotation)	Measured	77,496	0.70					5.38				545				13,394
	Indicated	94,808	0.56					4.14				530				12,608
	M&I	172,605	0.62					4.69				1,075				26,002
	Inferred	15,075	0.48					3.69				72				1,789
Oxides + Mixed (Dump Leach) 31-Dec-2025	Measured	16,206		0.35								57
	Indicated	51,110		0.19								99
	M&I	67,316		0.23								156
	Inferred	67,710		0.14								92

Total Measured and Indicated Mineral Resources												10,477	214	79	75	50,664	2,553	131
Total Inferred Mineral Resources												3,324	249	102	7	18,764	1,658	46

NOTES: Mineral Resources take into account mining activities to the effective date, where applicable and are reported insitu, using the 2014 CIM Definition Standards. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. Mineral Resources are reported inclusive of the Mineral Reserves. All Mineral Resources are exclusive to dilution and mining recovery factors. All contained metals are reported at 100% except as stated. Rounding as required by reporting guidelines may result in apparent summation differences between tonnes, grade and contained metal content. Grade TCu% refers to total copper grade in percent sent to the mill for metallurgical recovery by flotation. Grade SCu% refers to soluble copper grade in percent sent to the leaching processes. Grade ICu% refers to insoluble copper grade in percent, based on TCu% minus SCu%. Contained ounces (oz) are troy ounces. COG is cut-off grade. NSR is net smelter return. M&I = Measured & Indicated. All amounts in US$ unless otherwise specified. Stockpiled material is treated as Mineral Resources, described below. See Technical Reports filed under Capstone Copper’s profile on SEDAR+ for further information.

¹Garth Kirkham, P.Geo., FGC is the Qualified Person responsible for the Mineral Resource presented in the Pinto Valley Mine Technical Report, effective March 31, 2021. Klaus Triebel, GPG, Chief Resource Modeler at Pinto Valley Mine, oversaw depletion of the of Mineral Resource for mining activities as at December 31, 2025. Mineral Resources are reported at a 0.14% Cu cut-off grade. Economic assumptions for the reasonable prospects pit include: $3.50/lb Cu, $10.00/lb Mo, 84.6% Cu recovery, 8.9% Mo recovery, $1.74/tonne mining costs, $1.13/tonne G&A costs, $0.88/tonne operational support costs, $4.67/tonne milling costs, and pit slopes by rock type. Stockpile material is included as Measured Mineral Resource. Pinto Valley Mine is an open-pit mine with mineral processing by flotation.

²Clay Craig, P.Eng., Director, Mining & Strategic Planning at Capstone Copper is the Qualified Person responsible for the Mineral Resource in the Cozamin Mine Technical Report, effective January 1, 2023, and the depletion of the Mineral resource for mining activities as at December 31, 2025. Mineral resources are reported at a cut-off of NSR US$59/tonne. Metallurgical recoveries used in the NSR formulae are based on mineralization. Metallurgical recoveries vary by domain and NSR formula. Copper-silver dominant zones use the NSR formula: (Cu%*$70.72 + Ag g/t$0.53) * (1-NSR Royalty%). Copper-silver dominant zones use the following metallurgical recoveries: 96.16% Cu and 85.83% Ag. Copper–zinc zones use the NSR formula: (Cu%$69.74 + Ag g/t$0.50 + Zn%*$12.96) * (1-NSR Royalty%). Copper-zinc zones use the following metallurgical recoveries: 94.82% Cu, 83.82% Ag, 66.95% Zn, and 0% Pb. MNFWZ zinc–silver dominant zones use the NSR formula: (Ag g/t$0.35 + Zn%$16.80 + Pb%*$15.11) * (1-NSR Royalty%). Zinc–silver dominant zones use the following metallurgical recoveries: 66.50% Ag, 86.79% Zn, and 92.86% Pb. The NSR formula for MNV zinc zones is (Ag0.241 + Zn15.511 + Pb12.993)(1-NSRRoyalty%) using metallurgical recoveries of 55% Ag, 80% Zn and 80% Pb. The NSR formula for MNV copper-zinc zones is (Cu69.739 + Ag0.498 + Zn12.956)(1-NSRRoyalty%) using metallurgical recoveries of 95% Cu, 85% Ag and 67% Zn. The formulae include consideration of confidential current smelter contract terms, transportation costs and 1-3% net smelter return royalty payments. Metal price assumptions (in US$) used to calculate the NSR for all deposits are: $3.75/lb Cu, US$22.00/oz Ag, US$1.35/lb Zn and US$1.00/lb Pb. An exchange rate of MX$20 per US$1 is assumed. The NSR cut-off is based on operational mining and milling costs plus general and administrative costs. The Mineral Resource Estimate encompasses both the MNFWZ and the MNV. The Mineral Resource was estimated assuming underground mining by longhole stoping and post-pillar cut-and-fill with mineral processing by flotation. Stockpile material is included as Measured Mineral Resource. Mineral Resource estimates do not account for mining loss and dilution. All metals are reported as contained.

³Peter Amelunxen, P. Eng., Senior Vice President, Technical Services at Capstone Copper is the Qualified Person responsible for the Mineral Resource estimates for the Santo Domingo, Iris, Iris Norte and Estrellita deposits, effective March 31, 2024. Mineral Resources for the Santo Domingo, Iris and Iris Norte deposits are reported using a net smelter return (NSR) cut-off value of US$9.85/t. NSR is calculated using average long-term prices of US$4.10/lb Cu, US$1,600/oz Au, and Fe prices that depend on the expected grade of the Fe concentrate (US$94.75/dmt or $129.77/dmt or $140.26/dmt Fe concentrate). Mineral Resources are constrained by preliminary pit shells derived using a Lerchs–Grossmann algorithm and the following assumptions: pit slopes 36.3°- 47.9°; mining cost is calculated using a function that depends on where the material comes from (Santo Domingo or Iris Norte) and its destination (dumps, plant or stock); processing cost based on Fe concentrate routing code (including G&A costs); processing recovery based in the recovery equations for copper, gold, and iron as detailed above. For the Estrellita deposit,Mineral Resources are reported using an NSR cut-off value of US$9.63/t. NSR is calculated using average long-term prices of US$4.10/lb Cu and US$1,600/oz Au; only copper, and gold were considered in the NSR calculation(iron was excluded). Estrellita Mineral Resources are constrained by preliminary pit shells generated using a Lerchs–Grossmann algorithm and the following assumptions: pit slopes 43º; mining cost of US$1.55/t, processing cost of US$9.46/t (including G&A cost); processing recovery are calculated based in the recovery curves for copper and gold. The average Iron grades for the Project (Total Indicated, Total Measured plus Indicated, and Total Inferred Resources) cannot be calculated because Estrellita does not contain iron resources.

⁴Peter Amelunxen, P. Eng., Senior Vice President, Technical Services at Capstone Copper is the Qualified Person responsible for the Mineral Resource estimates at the Mantoverde Mine effective December 31, 2025. Mineral Resources are reported on a 100% basis. The attributable percentage to Capstone Copper is 69.993%. COG varies per zone and recovery process:
Flotation: Sulphide: TCu ≥ 0.20% and oxidation state=3, Mixed: TCu ≥ 0.20% and SCu/TCu ≤ 50% and oxidation state=2.
Dump Leach: Oxide: 0.10% ≤ SCu < 0.20% and oxidation state=1, Mixed 0.10% ≤ SCu < 0.20% and SCu/TCu > 50% and oxidation state=2.
Heap Leach: Oxide: SCu ≥ 0.20% and oxidation state=1, Mixed: SCu ≥ 0.20% and SCu/TCu > 50% and oxidation state=2.
Flotation recovery is based on a geometallurgical model, 90.44%TCu and 67.87% Au average for Sulphides and 72.77% TCu and 61.73% Au average for Mixed. Heap Leach recovery is based on operating data, expressed in algorithms per mineral model zone considering both SCu and CaCO₃ grades. The average heap leach recovery is 67.64% SCu, with an additional 50% metal recovered achieved through the bioleaching process. For dump leaching, the recovery averages 38.9% SCu, based on operational data. Dump recovery is 37.74%SCu (based on operating data). The Mineral Resource pit is based on $4.00/lb Cu and $1,700/oz Au based on long-term forecast pricing.

⁵Ronald Turner, MAusIMM (CP), a WSP employee, is the independent Qualified Person responsible for the Mineral Resource in the Mantos Blancos Mine Technical Report effective November 29, 2021. Guillermo Pareja, P.Geo, Manager, Resources Estimation at Capstone Copper, oversaw depletion of the Mineral Resource for mining activities as at December 31, 2025. Mineral Resources are reported on a 100% basis and included stockpiled material. The attributable percentage to Mantos Copper Holding SpA is 99.993%. COG varies by metallurgical process: Flotation at 0.22% Insoluble Cu, Dump Leach at 0.10% Soluble Cu. The Mineral Resource pit is based on US$3.75/lb Cu and US$20.00/oz Ag. Flotation recovery is based on a geometallurgical model, 83.4% TCu and 70.7% Ag as average. Dump recovery is based on average operational data at 42.4% SCu. Through the Osisko silver production agreement, Osisko Gold has the right to buy 100% of the silver production in concentrate, less specified deductions, until reaching 19.3 million ounces and subsequently 40% paying 92% of the market price.

Consolidated Estimated Mineral Reserves

Mineral Reserves												Contained Metal
	Category	kt	TCu %	SCu %	ICu %	Zn %	Pb %	Mo %	Ag g/t	Au g/t	Fe %	Cu kt	Zn kt	Pb kt	Mo kt	Ag koz	Au koz	Fe³ Mt
Pinto Valley¹ 31-Dec-2025	Proven	249,491	0.32					0.007				803			16
	Probable	50,724	0.30					0.005				150			3
	Total	300,215	0.32					0.006				954			19
Cozamin² 31-Dec-2025	Proven	42	1.82			0.21	0.02		38.0			1				52
	Probable	6,614	1.39			0.73	0.43		42.3			92	49	28		8,988
	Total	6,657	1.40			0.73	0.43		42.2			93	49	28		9,040
Santo Domingo³ 31-Mar-2024	Proven	130,945	0.52							0.07	27.2	675					291	13
	Probable	305,111	0.25							0.04	26.2	761					346	56
	Total	436,056	0.33							0.05	26.5	1,435					637	68
Mantoverde⁴ Sulphides + Mixed (Flotation)	Proven	209,871	0.55							0.10		1,146					675
	Probable	174,347	0.39							0.09		686					504
	Total	384,219	0.48							0.10		1,833					1,179
Oxides + Mixed (Dump+Heap Leach) 31-Dec-2025	Proven	125,411		0.21								259
	Probable	70,356		0.19								131
	Total	195,768		0.20								390
Mantos Blancos⁵ Sulphides + Mixed (Flotation)	Proven	53,048	0.70	0.09	0.61				5.59			374				9,539
	Probable	47,098	0.51	0.07	0.44				3.86			239				5,848
	Total	100,146	0.61	0.09	0.52				4.84			613				15,387
Oxides + Mixed (Dump Leach) 31-Dec-2025	Proven	1,147	0.51	0.32								4
	Probable	987	0.36	0.21								2
	Total	2,134	0.44	0.27								6
Total Mineral Reserves												5,323	49	28	19	24,427	1,816	68

NOTES: Mineral Reserves take into account mining activities as stated, where applicable. Rounding as required by reporting guidelines may result in apparent summation differences between tonnes, grade and contained metal content. Grade TCu% refers to total copper grade in percent sent to the mill for metallurgical recovery by flotation. Grade SCu% refers to soluble copper grade in percent sent to the leaching processes. Grade ICu% refers to insoluble copper grade in percent, based on TCu% minus SCu%. All Mineral Reserve estimates take into account dilution and mining recovery factors. Contained ounces (oz) are troy ounces. COG is cut-off grade. NSR is net smelter return. All amounts in US$ unless otherwise specified. Stockpiled material is included in the Mineral Reserves, described below. See Technical Reports filed under Capstone Copper’s profile on SEDAR+ for further information.

¹Clay Craig, P.Eng., Director, Mining & Strategic Planning at Capstone Copper, is the Qualified Person responsible for the Pinto Valley Mineral Reserve estimate as at December 31, 2025. Economic inputs to the block model were $3.00/lb per pound copper, $10.00/lb molybdenum, 86.0% average Cu recovery, 8.5% average Mo recovery, $1.68/tonne average mining costs, $1.13/tonne G&A costs, $0.88/tonne Ops Support costs, $4.67/tonne milling costs, and pit slopes by rock type. The Mineral Reserve is reported at a COG of 0.19% copper. Stockpiled material is included as Proven Mineral Reserve. Pinto Valley Mine is an open-pit mine with mineral processing by flotation.

²Clay Craig, P.Eng., Director, Mining & Strategic Planning at Capstone Copper, is the Qualified Person for the Cozamin Mine Mineral Reserve as at December 31, 2025. The Mineral Reserve is reported within fully diluted mineable stope shapes generated by the Deswik Mineable Shape Optimiser software. Mining methods include long-hole stoping and cut-and-fill methods. The Mineral Reserve is reported at or above a blended cut-off of US$60.54/t NSR for long-hole stoping, US$65.55/t NSR for cut-and-fill methods, and US$82.78/t NSR for MNV West cut-and-fill and long-hole stoping. The NSR cut-off is based on operational mining and milling costs plus general and administrative costs. The NSR formulae vary by zone. Four separate NSR formulae are used based on zone mineralization and metallurgical recoveries. Copper-silver dominant zones use the NSR formula: (Cu66.638 + Ag0.484)*(1-NSRRoyalty%), except the MNV West copper-silver zone, which uses the formula (Cu% * $70.724 + Ag g/t * $0.484) * (1-NSRRoyalty%)). MNFWZ zinc-silver zones use the NSR formula: (Ag0.290 + Zn13.723 + Pb13.131)(1-NSRRoyalty%). MNV zinc-silver dominant zones use the NSR formula: (Ag0.228 + Zn12.121 + Pb11.363)(1-NSRRoyalty%). Metal price assumptions of Cu = US$3.55/lb for MNV and MNFWZ, Cu $3.75/lb for MNV West, Ag = US$20.00/oz, Pb = US$0.90/lb, Zn = US$1.15/lb and metal recoveries of 96% Cu, 86% Ag, 0% Pb and 0% Zn in copper-silver dominant zones, 0% Cu, 61% Ag, 93% Pb and 88% Zn in MNFWZ zinc-silver dominant zones, and 0% Cu, 56% Ag, 80% Pb and 77% Zn in MNV zinc-silver dominant zones. The formulae include consideration of confidential current smelter contract terms, transportation costs and 1–3% net smelter return royalty payments. Royalties are dependent on the mining concession, and are treated as costs in the Mineral Reserve estimates. The Proven Mineral Reserve is stockpiled ore. Totals may not sum due to rounding.

³Peter Amelunxen, P.Eng., Senior Vice President, Technical Services at Capstone Copper is the Qualified Person responsible for the Santo Domingo Project Mineral Reserve effective March 31, 2024. Mineral Reserves are reported as constrained within Measured and Indicated Resources and pit designs optimized using the following economic and technical parameters: metal prices of US$3.75/lb Cu, US$1,400/oz Au and Fe prices ranging from US$69/dmt to US$114.51/dmt based on the Fe grade in concentrate (net of Fe concentrate transport costs); average recovery to concentrate is 90.1% for Cu and 56.3% for Au, with magnetite concentrate recovery varying on a block-by-block basis; copper concentrate treatment charges of US$80/dmt, U$0.08/lb of copper refining charges, US$5.0/oz of gold refining charges, US$40/wmt and US$25.75/dmt for shipping copper and iron concentrates respectively; waste and ore mining cost of $1.55/t and process and G&A+SUSEX of US$9.77/t processed; average pit slope angles that range from 36.3° to 47.9°; a 2% royalty rate assumption and an assumption of 100% mining recovery. No formal production has occurred from the Santo Domingo property area.

⁴Peter Amelunxen, P. Eng., Senior Vice President, Technical Services at Capstone Copper is the Qualified Person responsible for the Mineral Reserve at the Mantoverde Mine effective December 31, 2025. Mineral Reserves are reported on a 100% basis as constrained within Measured and Indicated Resources and pit designs included within the mine schedule. The attributable percentage to Capstone Copper is 69.993%. The block model is considered to be fully diluted and no dilution or mining losses are applied. The pit designs and mine plan were optimized using assumed metal prices of $3.50/lb Cu and $1,500/oz Au. Mineral Reserves for flotation are estimated above a 0.20% Total Copper (TCu) cut-off. Mineral Reserves for leach are estimated above a 0.10% Soluble Copper (SCu) cut-off for Dump leach, with a variable Heap cut-off between 0.16% and 0.21% SCu to reflect ore availability. Leach-grade material mined after 2037 was scheduled as waste. LOM feed to flotation averaged 87.7% total copper recovery and 65.3% gold recovery. Average heap leach recovery applied in Mine Planning was 71.5% of SCu and 50% of ICu, where ICu = TCu – SCu. Average dump leach recovery applied was 38.0% of SCu. Mineral Reserves considered the following average costs: mining cost of $1.87 per tonne moved; $10.11/t flotation processing+tails+G&A; $0.31/lb TC/RC+freight for flotation; $10.14/t heap+G&A; $1.78/t dump leach; $0.35/lb SX/EW costs; and $0.05/lb cathode selling cost. Heap leach Reserve figures include the costs and benefits of bioleaching; the contained metal reported in the table considers SCu only. This excludes insoluble copper, of which a portion is expected to be recovered from bioleaching in the heap leach process. Inter-ramp angles in rock vary from 52° to 59°. The LOM strip ratio is 2.7:1.

⁵Carlos Guzman, RM CMC, FAusIMM, an employee of NCL, is the independent Qualified Person responsible for the Mineral Reserve in the Mantos Blancos Technical Report effective November 29, 2021. Clay Craig, P.Eng., Director, Mining & Strategic Planning at Capstone Copper, oversaw depletion of the Mineral Reserve for mining activities as at December 31, 2025. The Mineral Reserve is based on average off-site costs (selling cost) of US$0.297/lb for sulphides and US$0.60/lb for oxides. Mineral Reserves are contained within an optimized pit shell. The estimated Mineral Reserves are reported using metal prices of US$3.50/lb Cu and US$20/oz Ag. Mining will use conventional open pit methods and equipment and a stockpiling strategy (direct mining costs are estimated at an average US$1.99/t of material mined). Processing costs average US$14/t of milled material, including concentrator, tailings storage facility and port costs. Processing cost for material sent to dump leach is US$2.26/t. TCu recovery averages 83.1% for sulphides and silver recoveries average 79.5%. SCu recovery of 42% was used in mine planning for material sent to the dump leach. Inter-ramp angles vary from 36˚ to 54˚in the sulphide zones and from 31˚ to 36˚ in the oxide zones . The life-of-mine strip ratio is 4.2 to 1 for the sulphide zones and 4.4 to 1 in the oxide zones. Through the Osisko silver production agreement, Osisko has the right to buy 100% of the silver production in concentrate (less specified deductions) until reaching 19.3 million ounces and subsequently 40% paying 92% of the market price. Stockpiled material is included in the Probable Mineral Reserve.