Chalcophanite Locality: Cole Mine (Cole shaft; Cole No. 3), Bisbee , Warren District , Mule Mts, Cochise County , Arizona , USA ( Locality at mindat.org ) Size: 5.5 x 4.2 x 3.4 cm. Chalcophanite is a rare zinc, iron, manganese hydroxide. This fine, 3-dimensional, mammilary crust from the Cole Shaft at Bisbee is composed entirely of sparkly, purplish-black chalcophanite botryoids. The very rich Cole Shaft produced ore intermittently from 1905 to 1975. Complete all-around and pristine, with only contacting at the base. Ex. Mark Bandy and Dave Stoudt Collections. Mark Bandy was a very prominent American mining engineer and mineral collector who died in 1963. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Chalcophanite
Chalcophanite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula ZnMn⁴⁺₃O₇·3H₂O.
It crystallizes in the hexagonal crystal system (space group R-3).
Key properties: Mohs hardness 2.5; specific gravity 4; Chocolate-brown streak; Metallic to submetallic luster; optically uniaxial.
IMA symbol Cph, grandfathered status — known before the IMA’s founding, named in 1875.
A common component of the weathered zones above zinc- and manganese-bearing base- metal deposits.
It is found associated with Cryptomelane, manganite, hetaerolite, birnessite, todorokite, woodruffite, kaolinite, quartz.
Its name comes from the Greek for copper and to appear, for the mineral's change in color on ignition.