The Cornet occurrence is underlain by massive amygdaloidal basalt of the Upper Triassic Karmutsen Formation (Vancouver Group) intruded by diorite dykes.

Mineralization consists of a few magnetite lenses developed in basalt containing pyrite and small quantities of chalcopyrite. A shaft was sunk on the largest lens which measured 30 metres in length.

A tunnel was started on the east coast of Texada Island to intersect the mineralization but was not completed.