Rappoldite Locality: Rappold Mine, Neustädtel, Schneeberg District, Erzgebirge, Saxony, Germany Field of view 5 mm Aggregate of reddish brown rappoldite crystals on quartz — Photo: Leon Hupperichs · CC BY-SA 3.0
Rappoldite
Rappoldite is an IMA-recognized mineral species in the arsenate class, with the chemical formula PbCo₂(AsO₄)₂·2H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Helmutwinklerite structural group.
Key properties: Mohs hardness 4.5; specific gravity 5.28; Light yellow-brown streak; Vitreous luster; optically biaxial.
IMA symbol Rap, IMA status: approved, named in 1998.
A secondary mineral.
It is found associated with Cobaltlotharmeyerite.
The name refers to the Rappold mine, where the first samples were collected.