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Loellingite
Chemical Formula	FeAs2
Species	Arsenic
Crystal System	Orthorhombic
Mohs Scale	5-5.5
Specific Gravity	7.1-7.5
Color	Seel grey to silvery white
Streak	Grayish black
Luster	Metallic
Cleavage	Rare, distinct on ,
Fracture	Uneven
Crystal Habit：Prismatic to pyramidal crystals, massive

Loellingite, also spelled l?llingite, is an iron arsenide mineral with formula FeAs₂. It is often found associated with arsenopyrite (FeAsS) from which it is hard to distinguish. Cobalt, nickel and sulfur substitute in the structure. The orthorhombic lollingite group includes the nickel iron arsenide rammelsbergite and the cobalt iron arsenide safflorite. Leucopyrite is an old synonym for loellingite.

It forms opaque silvery white orthorhombic prismatic crystals often exhibiting crystal twinning. It also occurs in anhedral masses and tarnishes on exposure to air. It has a Mohs hardness of 5.5 to 6 and a quite high specific gravity of 7.1 to 7.5. It becomes magnetic after heating.

Loellingite was first described in 1845 at the L?lling district in Carinthia, Austria, for which it was named.

It occurs in mesothermal ore deposits associated with skutterudite, native bismuth, nickeline, nickel-skutterudite, siderite and calcite. It has also been reported from pegmatites.