Löllingite - Encyclopedia
Class : Sulfides and sulfosalts
Subclass : Arsenides
Crystal system : Orthorhombic
Chemistry : FeAs2
Rarity : Uncommon
Löllingite (or loellingite) is an uncommon iron arsenide. It is mainly found in high temperature hydrothermal deposits, often in conjunction with granitic intrusions : gold, stanno-wolframiferous or polymetallic veins and sometimes in pegmatites and skarns. It owes its name to its locality of discovery : Lölling (Austria). Löllingite can form elongated, striated, bipyramid prismatic crystals, but usually occurs in flabelliform break masses, bacillary aggregates, or fibroradiated nodules. Its luster is metallic, its silver-white color tarnishing quite quickly to a light steel gray. Like arsenopyrite, it easily alters to scorodite in outcrops. It is sometimes an arsenic ore.
Main photo : 7 cm löllingite from Huanggang, Inner Mongolia, China © Rob Lavinsky
Löllingite in the World
Twinning
Twins are known on {001} and polysynthetics on {101}.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 5 to 5.5
Density : 7.43
Fracture : Sub-conchoidal
Streak : Gray-black
TP : Opaque
RI : -
Birefringence : -
Optical character : Biaxial -
Pleochroism : None
Fluorescence : None
Solubility : -
Magnetism : NoneRadioactivity : None