Campigliaite

Campigliaite is a copper and manganese sulfate mineral with a chemical formula of Cu4Mn(SO4)2(OH)6·4H2O. It is a rare secondary mineral in the oxidized zone of a metallic sulfide skarn deposit. It has a chemical formula and also a crystal structure similar to niedermayrite, with Cd(II) cation replacing by Mn(II).

The formation of campigliaite is related to the oxidation of sulfide minerals to form sulfate solutions with ilvaite associated with the presence of manganese. It is a rare secondary mineral formed when metallic sulfide skarn deposits are oxidized. While there are several related associations, there is no abundant source for this mineral due to its rare process of formation.

General Information

  • Category: Copper oxysalt mineral
  • Formula: Cu4Mn(SO4)2(OH)64H2O
  • Crystal system: Monoclinic
  • Crystal class: Spheroidal (2) (same H-M symbol)

Properties

Based on its crystallographic data and chemical formula, campigliaite is placed in the devillite group and considered the manganese analogue of devillite. It belongs to the copper oxysalt minerals as well followed by the subgroup M=M-T sheets. The infinite sheet structures that campigliaite has are characterized by strongly bonded polyhedral sheets, which are linked in the third dimension by weaker hydrogen bonds.

  • Color: Pale blue to pale greenish blue
  • Crystal habit: Typically as clusters or tufts of elongated or bladed crystals
  • Twinning: Polysynthetic, with {100} as twin plane, ubiquitous
  • Cleavage: Perfect on {100}
  • Luster: Vitreous
  • Specific gravity: 3.0

Geologic occurrence

The formation of campigliaite is related to the oxidation of sulfide minerals to form sulfate solutions with ilvaite associated with the presence of manganese. Campigliaite is closely associated with gypsum because of the geologic processes that form campigliaite.

In addition to the type locality, campigliaite has also been reported from the Biccia Mine in Alessandria Province, Piedmont, Italy, and from the Deer Trail Mine of the Tushar Mountains of Piute County, Utah, US.

 

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