Chalcopyrite, pyrite and sparse molybdenite occur in quartz veins accompanied by various combinations of chlorite, sericite, epidote, and carbonate. Host rock is an inner border phase of the Triassic Granite Mountain pluton, which has undergone pervasive saussurite-chlorite alteration. Four economic zones have been recognized and are in various stages of development and production; these are the Pollyanna, Granite Lake, Gibraltar East, and Gibraltar West zones. The general trend of deformation, alteration and mineralization is westerly and northwesterly.