Copper

Unknown Owner

Wonderful branching dendritic crystallized cluster of native copper. In excellent condition.The Central Mine, located on the Keweenaw Peninsula in Michigan, was one of the most successful and enduring fissure-vein copper mines in the Lake Superior region. Geologically, the site sits upon the massive basaltic flows of the Portage Lake Volcanics, where native copper was deposited within nearly vertical fissures that cut across the local rock strata. Unlike many neighboring mines that targeted amygdaloid or conglomerate lodes, Central Mine thrived by extracting high-grade mass copper and beautifully crystallized silver from these deep-seated fractures. Historically, the mine was discovered in 1854 when prospectors found an ancient pit containing a large mass of copper, and it remained in continuous operation until 1898. The mining village of Central once housed over twelve hundred residents, primarily Cornish miners whose expertise was vital for navigating the challenging fissure deposits. Today, the Central Mine site is a key part of the Keweenaw National Historical Park, preserved as a ghost town that serves as a testament to the nineteenth-century copper boom and the unique geological conditions that fueled Michigan's industrial heritage.