Adamite
Image: Didier Descouens (CC BY-SA 3.0)
Mineral NameAdamite
Chemical FormulaZn₂AsO₄(OH)
Mohs Hardness3.5
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavagegood on {101}, poor on {010}
Fractureuneven
Specific Gravity4.35
Colorsyellow-green, lime green, pale yellow, white
Transparencytransparent
Type LocalityOjuela Mine, Mapimí, Durango, Mexico
Mineral GroupArsenates
Usescollector
Associated Mineralslimonite, goethite, calcite, smithsonite
Rarityuncommon
Description
This specimen features vibrant lime-green to pale yellow-green adamite crystals, some forming botryoidal clusters and others as distinct prismatic crystals, embedded within a reddish-brown iron oxide matrix.
Geological Context
Adamite is a secondary mineral that forms in the oxidized zones of zinc-arsenic ore deposits, typically resulting from the alteration of primary zinc and arsenic-bearing minerals in hydrothermal environments.
