Photographs and photomicrographs of microstructures from the Yuka gold deposit. (a) Gold quartz vein. (b) Gold-containing altered mylonite. (c) Stage-II quartz and sericite schist. (d) Stage-I quartz and stage-II quartz. (e) Stage-II quartz and stage-III calcite+quartz. (f) Stage-I pyrite and stage-II pyrite with chalcopyrite. (g) Stage-II pyrite with native gold. (h) Cubic crystal stage-I pyrite. Abbreviation: Mal = malachite; Qtz = quartz; Py = pyrite; Ccp = chalcopyrite; Cal = calcite.