Capstone Copper Closes San Pietro Buy to Hit 60,000ha Chile District
Key Takeaways
- Capstone Copper closed the San Pietro acquisition on 31 August 2026, paying $25 million in shares at C$15.77 per share — a fully scrip-funded deal that preserves cash.
- San Pietro adds approximately 16,000 hectares of copper concessions, bringing Capstone's total owned district footprint to approximately 60,000 hectares, plus a further 18,000 hectares under the ENAMI option agreement.
- The Rincones and Colla deposits at San Pietro carry an NI 43-101 compliant Inferred Mineral Resource of 492 Mt at 0.23% Cu, containing 4,444 million pounds of copper.
- San Pietro sits within a 20km radius district already containing approximately 1.6 billion tonnes of Measured and Indicated Resources and 1.4 billion tonnes of Inferred Resources, with existing and permitted infrastructure already in place at Mantoverde and Santo Domingo.
- This is Capstone's third district consolidation move in three years, following the Sierra Norte acquisition in 2024 and the ENAMI exploration option agreement in 2025.
Capstone completes San Pietro acquisition, consolidating the Mantoverde-Santo Domingo copper district
Capstone Copper Corp. formally closed the acquisition of the San Pietro copper-gold-iron-cobalt project on 31 August 2026, paying total consideration of $25 million in Capstone shares (2,034,970 shares at a deemed value of C$15.77 per share, being the 10-day volume-weighted average closing price ending two business days before closing of the transaction net of applicable withholding taxes). San Pietro is strategically positioned in Chile’s Atacama Region between Capstone’s Mantoverde, Santo Domingo, and Sierra Norte properties, and the transaction represents another step in the company’s ongoing consolidation of the Mantoverde-Santo Domingo District, following the Sierra Norte acquisition in 2024 and the ENAMI exploration option agreement in 2025.
Cashel Meagher, President and Chief Executive Officer
“Capstone’s acquisition of San Pietro marks another step in the consolidation of the Mantoverde-Santo Domingo District. Located adjacent to Santo Domingo, and between Mantoverde and Sierra Norte, the Project is a natural fit within a region where we have existing and permitted infrastructure, deep knowledge of the local geology, and an experienced operating and project development team. Following our acquisition of Sierra Norte in 2024 and the exploration option agreement signed with ENAMI in 2025, this Transaction further expands our footprint in the top-tier region of the Atacama. We look forward to integrating San Pietro into our district exploration and development plans as we pursue opportunities to unlock transformational copper production growth.”
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What San Pietro adds to the MV-SD District
Land package and strategic positioning
San Pietro contributes approximately 16,000 hectares of highly prospective, underexplored copper concessions to Capstone’s existing land position. The combined district footprint now totals approximately 60,000 hectares owned outright, plus a further approximately 18,000 hectares under the ENAMI option agreement.
Within a approximately 20km radius centred on the Mantoverde-Santo Domingo District, Capstone’s mineral concessions contain approximately 1.6 billion tonnes of Measured and Indicated Mineral Resources inclusive of Mineral Reserves, in addition to approximately 1.4 billion tonnes of Inferred Mineral Resources. San Pietro sits within this footprint, positioned between established deposits with existing and permitted infrastructure already in place.
Rincones and Colla mineral resource
San Pietro hosts the Rincones and Colla deposits, which together carry an NI 43-101 compliant Inferred Mineral Resource with an effective date of 24 January 2025, prepared by independent qualified persons Dr. Bruce David (PhD, FAusIMM) and Susan Lomas (P.Geo) for Golden Arrow Resources Corporation.
| Category | Tonnes (Mt) | Cu (%) | Au (g/t) | Contained Cu (Mlb) |
|---|---|---|---|---|
| Inferred – Oxide | 83 | 0.23% | 0.06 | 759 |
| Inferred – Sulphide | 410 | 0.23% | 0.05 | 3,686 |
| Total | 492 | 0.23% | 0.05 | 4,444 |
The resource is reported within a US$4.80/lb Cu pitshell at a 0.30% CuEq cut-off grade. Importantly, Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. The San Pietro deposit will require further evaluation, including drilling, to verify the resource estimate.
Understanding district-scale copper consolidation — why it matters to investors
District-scale consolidation means a single operator controls a contiguous land package spanning multiple deposits across a region. Rather than each deposit being developed in isolation, one company can coordinate exploration, development, and production across the entire area.
The practical benefit is shared infrastructure. Capstone has identified potential synergies and the opportunity to leverage existing and planned district infrastructure to enable multiple pathways for future optionality to be executed.
It’s also worth understanding what an Inferred Mineral Resource actually represents. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. Further drilling and technical study is required before any economic assessment can be made.
For Capstone, the relevance of San Pietro extends beyond the 492 Mt resource figure. Existing and permitted infrastructure at Mantoverde and Santo Domingo creates potential future optionality to process incremental oxide and sulphide feed from San Pietro, if future studies support it. No such decision has been made, and this remains a forward-looking possibility only.
The full district now includes:
- Mantoverde (operating copper-gold mine)
- Santo Domingo (fully permitted copper-iron-gold project)
- Sierra Norte (acquired 2024)
- ENAMI option (approximately 18,000 hectares)
- San Pietro (acquired 31 August 2026)
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Investment thesis — what comes next
Capstone plans to integrate San Pietro into its district exploration and development plans, though this remains forward-looking and subject to the outcomes of further technical work. A recommended exploration programme is anticipated to define a higher-grade portion within the existing 492 Mt resource footprint.
Beyond the defined resource, Capstone has identified several additional highly prospective copper exploration targets at San Pietro along regional structures associated with mineralisation at Mantoverde, Santo Domingo, and Sierra Norte. That exploration upside is incremental to the existing inventory.
The transaction structure itself is worth noting. Capstone paid $25 million in Capstone shares. The company separately describes the acquisition as “cost-effective.”
Capstone’s broader operating portfolio gives context to the scale of the company behind this district-building strategy. Its producing assets include the Pinto Valley copper mine in Arizona, the Cozamin copper-silver mine in Zacatecas, Mexico, the Mantos Blancos copper-silver mine in Chile’s Antofagasta region, and the Mantoverde copper-gold mine in the Atacama. The stated corporate strategy is to unlock transformational copper production growth while executing on cost and operational improvements through innovation, optimization and safe and responsible production throughout its portfolio of assets.
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