Annabergite
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 3.0)
Mineral NameAnnabergite
Chemical FormulaNi₃(AsO₄)₂·8H₂O
Mohs Hardness1.5
Crystal Systemmonoclinic
Lustervitreous
Streak Colorpale green to whitish
Cleavageperfect on {100}
Fractureuneven
Specific Gravity3
Colorsapple-green, yellowish-green, white
Transparencytransparent
Type LocalityKm-3 Mine, Lavrion Mines, Lavrion (Laurion; Laurium), Lavrion District Mines, Lavrion (Laurion; Laurium) District, Attikí (Attica; Attika) Prefecture, Greece
Mineral GroupArsenates
Usescollector
Associated Mineralsquartz, limonite, erythrite, native arsenic
Rarityuncommon
Description
The image shows vibrant apple-green, acicular to bladed crystals of Annabergite forming radiating aggregates, set against a matrix of reddish-brown and clear to whitish crystalline material.
Geological Context
Annabergite is a secondary mineral that forms in the oxidized zone of nickel-arsenic ore deposits, resulting from the alteration of primary nickel arsenides or nickel-bearing sulfides.
