Copper

Unknown Owner

A cluster of very sharp well defined crystals of native copper, some of these quite large measuring to 4.0 cm in size. In super condition all around.The Quincy Mine, located in Hancock within Houghton County, Michigan, is one of the most famous copper mines in the United States and is often called "Old Reliable" for its consistent dividend payments. Geologically, the mine exploited the Pewabic Lode, a mineralized amygdaloidal flow within the Precambrian-aged Portage Lake Volcanics. Native copper filled the gas bubbles (amygdules) and brecciated zones of ancient basaltic lava flows, accompanied by minerals like epidote, quartz, and occasional silver. Historically, the Quincy Mining Company was incorporated in 1848 and began significant production in the 1850s. The mine was a marvel of engineering, featuring the world's largest steam-driven mine hoist and shafts that eventually reached over 9,000 feet in depth. Operations continued through many economic cycles until the main mine finally closed in 1945 due to the depletion of profitable ore and rising costs following World War II. Today, the Quincy Mine is a National Historic Landmark and a primary site within the Keweenaw National Historical Park, where its massive hoist house and shaft headframe stand as icons of the Lake Superior copper boom.