Copper

specimen number:
1791305

location:
Ojibway Mine, Keweenaw Co., Michigan, USA

description:

Nicely crystallized native copper on matrix. In good condition. Choice thumbnail for this classic material.

The Ojibway Mine, located in Keweenaw County, Michigan, was organized in 1907 and operated underground through thirteen levels before closing in 1913 due to financial and investor challenges rather than a lack of ore. Geologically, the mine is situated within the Keweenaw Peninsula's Precambrian Keweenawan rift sequence, consisting of ancient, tilted basalt lava flows and interbedded sedimentary conglomerates. Native copper mineralization occurs primarily as open-space fillings within amygdaloidal tops of basalt flows and fault zones, accompanied by secondary minerals such as calcite, quartz, and occasional silver.

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