Malachite

specimen number:
8311470

location:
Cole Shaft, Bisbee, Cochise Co., Arizona, USA

description:
Velvety green botryoidal crystallized malachite covering all sides of matrix. In good condition.

The Cole Shaft, located in the Warren District of Bisbee, Cochise County, Arizona, is a prominent historical site within the Mule Mountains mineral system. Geologically, the shaft provided access to massive sulfide replacement deposits and secondary oxide ores hosted within the Paleozoic Martin and Abrigo Limestones, which were mineralized by fluids originating from the nearby Sacramento Hill porphyry copper complex. The mine is well-known to mineralogists for producing exceptional specimens of native copper, cuprite, and various carbonates such as malachite and azurite. Historically, the shaft was named after Thomas F. Cole and was a primary operation of the Superior and Pittsburg Mining Company before being absorbed by the Calumet and Arizona Mining Company, and eventually Phelps Dodge. Active mining and quarrying operations at the Cole Shaft were most significant from the early 1900s through the mid-20th century, with the shaft serving as a critical production and ventilation hub until underground operations in the district began to scale back in the 1970s. As of 2026, the Cole remains a celebrated locality for its historical contribution to Arizona's copper output and its legacy of producing world-class mineral specimens.

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