Hydrothermal quartz-gold vein sample (3.2 cm across) from the Harvard Open Pit Mine, northwestern side of Rt. 49/Rt. 108, western side of Woods Creek, just west of Jamestown, western Tuolumne County, Sierra Nevada foothills, central California, USA (37° 56’ 50” North , 120° 36’ 20” West).

Geology - hydrothermal quartz-gold veins of the Mother Lode Gold Belt occur in the Melones Fault Zone (= boundary between the Foothills Terrane and the Don Pedro Terrane). To the east of the fault zone is Jurassic slates. To the west of the fault zone is serpentinite melange.