"Specularite was found in quartzite on the slope above the Evans Tunnel, and it occurs plentifully in the Highland Boy mine in limestone adjacent to fissures of the great east-west fracture zone. It is a finely cleavable variety that occurs in masses associated with magnetite, chalcopyrite, and pyrite, and included by bands of hematite. It also occurs in radiating foils mingled with chalcopyrite and pyrite, replacing calcareous wall rock adjacent to minor fractures." (Boutwell, 1905, p. 205).