The mine also has additional reserves amounting to 7.3 million tonnes of ore grading 2.76% lithium.

[2] Cabot Corporation bought the mine in 1993, and began the production of caesium brine from pollucite in 1996.

[1] The pegmatite found at the north west shore and below the lake floor of Bernic Lake is a granitic igneous rock enriched in the incompatible elements, for example caesium, lithium, tantalum and beryllium.

Pegmatite forms if magmatic rock slowly crystallizes, and the incompatible elements are concentrated in the residual molten magma.

Examples of minerals found in the mine are the lithium-containing spodumene and amblygonite, caesium-containing pollucite, beryllium-containing beryl and tantalum- and niobium-containing simpsonite and tantalite.