Composition: Cu4(SO4)(OH)6.2H2O
Crystal System : Monoclinic
Colours: Sky-blue, greenish-blue
Lustre : Vitreous
Hardness (H) : 2.5-3.0
Specific Gravity (S.G) : 3.31
References: Gebhard (1999)


Rare. First, second and possibly third (?) oxidation zones.


  • Supergene
  • 1st Oxidation Zone
  • 2nd Oxidation Zone
  • 3rd Oxidation Zone

Paragenetic and General Notes

As blue crystals to 1 mm on corroded pseudomorphs of tennantite after enargite (Gebhard, 1999).

As bright-blue bladed crystals with brochantite and devilline (Pinch and Wilson, 1977).

Hard to distinguish from posnjakite.