Azurite , Chalcoalumite Locality: Calumet and Arizona Mine (Junction Mine; Junction shaft), Calumet and Arizona group of claims (Calumet and Arizona Mining Company group of claims), Bisbee , Warren District , Mule Mts, Cochise County , Arizona , USA ( Locality at mindat.org ) The truly neat thing about this specimen is that it can be viewed on either side, equally as well. On one side, a botryoidal crust of rich, blue, azurite is coated with a botryoidal crust of light green, chalcoalumite, a fairly rare, hydrous, copper, aluminum,sulfate. Here the chacoalumite spheres reach .8 cm across. On the back side is a vug with a crust of brown limonite upon which is emplaced a druse of sparkling, deep blue, spheres of azurite. Unusual, and very fine! 7.8 x 5.8 x 3.7 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Chalcoalumite
Chalcoalumite is an IMA-recognized mineral species in the sulfate class, with the chemical formula CuAl₄(SO₄)(OH)₁₂·3H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1). It is a member of the Chalcoalumite structural group.
Key properties: Mohs hardness 2.5; specific gravity 2.29; White streak; Vitreous to dull luster; optically biaxial.
IMA symbol Cca, grandfathered status — known before the IMA’s founding, named in 1925.
A rare secondary mineral found in the oxidized portions of copper deposits.
It is found associated with Cuprite, malachite, azurite, goethite (Bisbee, Arizona, USA); mbobomkulite, hydrombobomkulite (Mbobo Mkulu Cave, South Africa).
The name refers to essential chemical components, from the Greek chalkos, for copper and Latin alum, for aluminum sulfate.