Löllingite “Loellingite”

Löllingite with Fluorite and Arsenopyrite Huanggang Mines, Kèshíkèténg Qí, Chifeng, Inner Mongolia A.R.  China (2012) Specimen size: 7.5 × 6.5 × 6.2 cm = 3.0” × 2.6” × 2.4” Main crystal size: 5.8 × 5.7 cm = 2.3” × 2.2” © Fabre Minerals

Chemical Formula: FeAs2
Locality: Lölling, Hüttenberg, Carinthia, Austria
Name Origin: Named after its locality.

Loellingite, also spelled löllingite, 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 Lölling 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.

History

Discovery date : 1845
Town of Origin : MINE WOLFBAUER, LOLLING, HUTTENBERG, CARINTHIE
Country of Origin: AUTRICHE

Optical properties

Optical and misc. Properties: Opaque
Reflective Power: 51,7-54,2% (580)

Physical Properties

Cleavage: {001} Distinct
Color:     Silvery white, Tarnish gray.
Density: 7.1 – 7.7, Average = 7.4
Diaphaneity: Opaque
Fracture: Uneven – Flat surfaces (not cleavage) fractured in an uneven pattern.
Hardness: 5 – Apatite
Luminescence: Non-fluorescent.
Luster: Metallic
Magnetism: Magnetic after heating
Streak: grayish black

Photos :

Arsenic crystals with Loellingite St. Andreasberg, Harz Mountains, Germany Miniature, 4.7 x 3.1 x 3.0 cm © irocks
Löllingite Crovino mine, Susa valley, Piedmont, Italy Specimen weight:30 gr. Crystal size:2 mm Overall size: 50mm x 32 mm x 28 mm © minservice
Löllingite Huanggang nr. 1 mine – Chifeng – Inner Mongolia – China Specimen weight:314 gr. Crystal size:mm. 24 Overall size: 72mm x 55 mm x 35 mm © minservice
Carlés Mine, Carlés, Salas, Asturias, Spain © JRGL
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