Caesium at Shaakichiuwaanaan
Lithium anchors PMET’s development strategy at Shaakichiuwaanaan; alongside it, significant caesium and tantalum resources create opportunities
Caesium
The largest pollucite-hosted caesium resource in the world
Shaakichiuwaanaan is home to the largest pollucite-hosted caesium pegmatite Mineral Resource in the world, offering an important potential supply with significant by-product lithium and tantalum value, an exceptionally rare and strategic asset for North America’s critical mineral future.
Mineral Resource Estimate (Caesium Zone MRE1):
Rigel Zone
- 163,000 t grading 10.25% Cs₂O, 1.78% Li₂O and 646 ppm Ta₂O₅ (Indicated)
Vega Zone
- 530,000 t at 2.61% Cs₂O, 2.23% Li₂O, 172 ppm Ta₂O₅ (indicated)
- 1,698,000 t at 2.40% Cs₂O, 1.81% Li₂O, 245 ppm Ta₂O₅ (Inferred)
Caesium Content
- Contained Cs₂O: approximately 30.5 kt (Indicated) and 40.8 kt (Inferred)
Mineralization Evidence
- Extremely high-grades including 22.69% Cs₂O over 1 m at the Rigel Zone—highlighting the high-grade potential of the deposit.
Strategic Importance & Market Dynamics
caesium is listed as a critical mineral by both the U.S. and Canadian governments due to its geopolitical and technological importance. Demand is high and supply very limited. Supply security is a concern: China currently controls over 70% of processing capacity, and disruptions could impact industries reliant on caesium.
An important, high-value critical mineral
Caesium serves a small but strategically important market spanning drilling fluids, industrial catalysts, and specialty chemicals. Its commercial opportunity depends on both the availability of suitable mineral resources and the ability to deliver qualified products reliably.
OnG Commodities estimates current annual demand for new caesium supply at approximately 1,600 tonnes of caesium oxide equivalent (Cs₂O). Drilling brines account for approximately 55% of demand, followed by sulphuric acid catalysts at 29% and fine chemicals at 13%.
These applications provide an established customer base. They also help explain why dependable new supply could matter: manufacturers and industrial users need confidence in long-term availability before committing to products and processes that depend on caesium.
How a large, new supply from PMET could support market growth
Caesium formate is used in demanding high-pressure, high-temperature oil and gas wells. PMET’s market assessment identifies an opportunity to expand its availability beyond the established North Sea market into other suitable offshore basins. Other opportunities include sulphuric acid catalysts and specialty chemicals. Emerging applications, including certain perovskite solar-cell technologies, could provide additional demand over time.
Having a new, important source of supply like the resource at Shaakichiuwaanaan could significantly expand the current and future markets.
PMET’s opportunity at CV13
The Rigel and Vega zones at CV13 host a substantial pollucite-bearing caesium resource. Pollucite is the ideal caesium-bearing mineral and PMET is evaluating concentrate production and potential subsequent conversion into caesium chemicals.
The company has already disclosed successful test results with Koch Technology Solutions to produce multiple caesium end-products from Shaakichiuwaanaan’s pollucite.
Developing supply alongside demand
Resource size is only one part of the opportunity. PMET’s approach also recognizes the importance of customer commitments, product qualification, inventory requirements and a production pace aligned with market development.
The broader CV5+CV13 PEA, targeted for Q4 2026, will evaluate a development scenario incorporating lithium, caesium, and tantalum concentrate production. It will assess the potential role of CV13 within the Project’s mining sequence.
1 PMET declared a maiden Mineral Reserve at Shaakichiuwaanaan of 84.3 Mt at 1.26% Li2O (Probable). Probable Mineral Reserve cut-off grade is 0.40% Li2O (open-pit) and 0.70% Li2O (underground). Underground development and open-pit marginal tonnage containing material above 0.37% Li2O are also included in the statement. Effective Date of September 11, 2025. Shaakichiuwaanaan’s Consolidated MRE (CV5 + CV13 pegmatites), which includes the Rigel and Vega caesium zones, totals 108.0 Mt at 1.40% Li2O, 0.11% Cs2O, 166 ppm Ta2O5, and 66 ppm Ga, Indicated, and 33.4 Mt at 1.33% Li2O, 0.21% Cs2O, 155 ppm Ta2O5, and 65 ppm Ga, Inferred, and is reported at a cut-off grade of 0.40% Li2O (open-pit), 0.60% Li2O (underground CV5), and 0.70% Li2O (underground CV13). A grade constraint of 0.50% Cs2O was used to model the Rigel and Vega caesium zones. The Effective Date is June 20, 2025 (through drill hole CV24-787). Mineral Resources are not Mineral Reserves as they do not have demonstrated economic viability. Mineral Resources are inclusive of Mineral Reserves.