PMET Resources (ASX:PMT) has reported multiple new lithium-caesium-tantalum pegmatite discoveries across its James Bay properties in Québec.
The company announces the discovery of the Cosma caesium pegmatite, situated approximately 22km west of its CV5 Pegmatite Deposit on the Shaakichiuwaanaan Property.
Surface sampling returned an outcrop grab assay of 9.42% caesium oxide and 267 parts per million (ppm) tantalum pentoxide.
Channel sampling delivered 4.4m at 3.61% caesium oxide and 609ppm tantalum pentoxide, including 0.5m at 16.43% caesium oxide.
The company also reports the emerging Felix spodumene pegmatite discovery near the western margins of Shaakichiuwaanaan, proximal to the Pikwa Property.
Outcrop assays from the site include 1.80% lithium oxide and 1.21% lithium oxide across multiple mineralised outcrops over a 450m trend.
Collectively, the Cosma, Felix, and Drakkar lithium-caesium-tantalum pegmatite clusters extend the prospective Mickel Trend to approximately 10.5km in length, with only 450m of strike drill tested at CV9.
Additional discoveries include the Skald spodumene pegmatite at the Pontois Property, returning an outcrop assay of 2.94% lithium oxide; and the Overload caesium pegmatite at the Pontax Property, with an outcrop assay of 7.53% caesium oxide and 3,768ppm tantalum pentoxide.
Executive Vice President for Exploration Darren Smith says the recent surface exploration at Shaakichiuwaanaan has delivered multiple discoveries with strong results that continue to support the scale and growth potential for lithium, caesium, and tantalum across the property.
The discovery of a new caesium-rich LCT pegmatite occurrence (Cosma) lies along the highly prospective Mickel Trend, which also hosts the CV9, CV10, CV14, and CV15 pegmatites.
Smith notes that this supports the presence of a large, highly evolved, and fertile LCT pegmatite system within the western area of the property, an area that has seen limited drill testing to date.
The Drakkar LCT Pegmatite, discovered by Azimut Exploration (TSX-V:AZM) and SOQUEM, returned 2.45% lithium oxide in outcrop and is situated approximately 550m to the southwest of the Felix Pegmatite on the adjoining Pikwa Property, which is now held 100% by the company.
PMET Resources is currently planning follow-up surface work in 2026 at its Shaakichiuwaanaan, Pikwa, and Eastmain properties and is evaluating options for the next stage of exploration at Pontax.
Write to JC Villarba at Mining.com.au
Images: PMET Resources



