The area is underlain by cherty tuff, crystal tuff, chert and argillite of the Mississippian to Pennsylvanian Fourth Lake Form- ation, Buttle Lake Group (formerly the Sediment-Sill Unit of the Sicker Group). The area is intruded by sills and dykes of diabase and gabbro (informally called the Mount Hall Gabbro) that are coeval with the Upper Triassic Karmutsen Formation, Vancouver Group.

The Patricia deposit consists of a rhodonite lens, 1 metre thick, made up of massive, pink to brown, fine to predominantly very coarse-grained rhodonite. Calcite and pyrite veins as well as fracture-filled black oxides cut the lens. Anthophyllite, confirmed by x-ray diffraction analysis, is found on some weathered surfaces. The deposit adjoins the Hollings deposit (092B 074) to the southeast and is reported to be of similar nature. As of 1973, the deposit had not been extensively opened up, with limited production occurring.