Gold

specimen number:
2262314

location:
Gold Hill, Boulder Co., Colorado, USA

description:
A small but nice crystallized grouping of native gold.

he Gold Hill mining district, located in the mountains of western Boulder County, Colorado, was a pioneering and highly productive producer of gold and silver. Geologically, the district occupies the northern end of the Colorado Mineral Belt, where Late Cretaceous to Paleogene-age monzonite and granodiorite porphyry dikes intruded ancient Proterozoic granites and gneisses. This intrusive activity produced complex epithermal and mesothermal vein networks that are mineralogically famous for containing high-grade gold-telluride minerals, such as petzite, sylvanite, and calaverite, along with native gold and silver-bearing sulfides hosted in a quartz gangue. Historically, the district exploded into prominence following the January 1859 discovery of rich placer gold deposits in Gold Run, which triggered one of the earliest major rushes of the Colorado Gold Rush and led to rapid surface quarrying. Underground shaft mining expanded rapidly after the 1872 discovery of the complex telluride ores, which required specialized roasting and smelting mills to process. Famous operations like the Red Cloud, Cold Spring, and Horsfal mines utilized deep vertical shafts to extract high-grade ore, operating aggressively through the late nineteenth century and experiencing brief periods of revival during the 1930s. Due to declining ore grades at depth, high pumping costs, and changing global economics, large-scale industrial corporate extraction steadily contracted after World War II, culminating in the general cessation of major commercial mining operations by the late 1950s, though localized specimen recovery and environmental remediation projects continue intermittently.

Questions about this specimen?
Send an email or call us: 314-341-1811.