RAMMELSBERGITE
Class : Sulfides and sulfosalts
Subclass : Arsenides
Crystal system : Orthorhombic
Chemistry : NiAs2
Rarity : Rare
Rammelsbergite is a nickel arsenide found in medium temperature hydrothermal veins containing cobalt, nickel and often silver. It is associated with other white arsenides such as skutterudite and safflorite, with nickeline and native bismuth. It is a polymorph of pararammelsbergite and krutovite. It was named in honor of the German chemist and mineralogist Karl Friedrich Rammelsberg. Rammelsbergite is generally massive with a fine-grained to fibroradiated structure, tin-white in color with a slight pinkish tint. Its crystals are rare, in short prisms measuring up to 1 mm and seem to constantly show polysynthetic twins. It is a locally important nickel ore.
Main photo : Pyrostilpnite from the Clara Mine, Germany © Carsten Slotta
Rammelsbergite in the World
Twinning
Twins are known on {101}. Rammelsbergite pseudomorph after native silver are reported.
Fakes and treatments
No fakes listed for this mineral species.
Hardness : 5.5 to 6
Density : 7 to 7.2
Fracture : Irregular
Streak : Gray-black
TP : Opaque
RI : -
Birefringence : -
Optical character : -
Pleochroism : None
Fluorescence : None
Solubility : -
Magnetism : NoneRadioactivity : None