Copper (post-mining) | Bisbee, Arizona

Post-Mining Precipitated Crystalline Native Copper with Tubules – Phelps Dodge mines, Bisbee, Arizona

This unique copper specimen is a fine example of a ‘mine precipitated’ mineral specimen. This occurs where acidic copper-rich mine waters, also called “copper water,” chemically deposit metallic copper directly within the mine environment. Unlike traditional crystallized copper formed over geological time, this material is created as reactive copper-laden solutions encounter oxygen or exposed metal surfaces underground.

The result is a “natural electroplating,” producing intricate, metallic growths that resemble capillaries or coral-like growths. These remarkable formations are sometimes referred to as “mine copper.” At some historic Bisbee mines, the Copper Water was so prolific that miners harvested copper directly from solution by pouring it over scrap metal (such as tin cans), allowing the copper to precipitate out for later smelting. 

Distinctive features include a 90° bend from its attachment to a mine relic and elongated hollow tubules below, giving it a vascular appearance. This piece exemplifies Bisbee’s unique post-mining mineral formations and is ideal for collectors interested in Bisbee minerals, copper oddities, or post-mining mineral formations.