Calcite

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Fine crystallized grouping of calcite from this famous locality. In good condition. Complete all around. The Southwest mine, located in the Warren mining district of Bisbee, Arizona, is situated within Paleozoic limestones that were intruded by the Jurassic-era Sacramento Hill porphyry stock. This geologic event triggered extensive mineralization, forming pipe-like copper, lead, and zinc replacement bodies clustered around a highly siliceous core. Surface rainwater later percolated through these deposits, oxidising the primary sulfides into rich secondary ores and creating notable dissolution caves. Historically, the mine was operated under the Copper Queen Branch of Phelps Dodge. One of its most significant milestones occurred in 1918 when miners discovered the New Southwest orebody, also known as the Ballpark stope, which yielded approximately one million tons of high-grade copper oxide ore before its pillars collapsed in 1932. While underground mining eventually ceased as operations in the district shifted toward open pits, the Southwest mine remains well known to mineralogists for producing outstanding specimens of azurite, malachite, calcite, and rare halide-bearing species.