OLINGHOUSE MINE GOLD
Olinghouse gold - small gold mass at upper left (see arrows on photo
below) among small quartz crystals in hydrothermal vein. The original
vein consisted of quartz, gold, and calcite. The calcite was dissolved
away by acids during specimen preparation.
This gold-bearing sample is from the Olinghouse Gold
Mine in Nevada, USA. Rocks in the Olinghouse area are mostly late
Paleogene and Neogene lava flows. The lavas have been faulted by Basin
& Range extensional tectonics and mineralized by hydrothermal activity
peripheral to some large igneous intrusions.
This rock is not technically a gold ore sample.
It is one of many specimen gold samples from Olinghouse Mine that were
intentionally saved & prepared solely for mineral collectors.
Specimen gold from Olinghouse consists principally of wire gold and nest
gold. Nest
gold consists of loose aggregates of irregularly twisted gold wires.
Stratigraphy: fracture-filling hydrothermal quartz & gold in greenish altered
andesite, Pyramid Sequence, Middle Miocene.
Age of gold mineralization: early Late Miocene, 10-11 m.y.
Locality:
Green Hill pit, Olinghouse Mine, northwest of Wadsworth, southern Pah Rah
Range, southern Washoe County, western Nevada, USA. (~39º 39’ 44” N, ~119º 25’
07” W)
Greenish-gray altered andesite (flip side of above specimen) - this is the host rock
for the quartz-gold hydrothermal vein shown above.
Info. mostly synthesized from:
Kleine (2004) - Specimen gold from the Olinghouse
District, Washoe County, Nevada. Rocks & Minerals 79(1):
44-53.