Löllingite

lollingite

skutterudite

safflorite

bismuth

Images

Formula: FeAs2
Oxidation states: Fe2+As1-2 (AM 87.1692-1698)
Arsenide, löllingite group
There is complete solid solution between safflorite and löllingite, limited solution of cobalt in rammelsbergite and no solid solution between löllingite and rammelsbergite (AM53.1856, Mindat).
Crystal System: Orthorhombic
Specific gravity: 7.43 measured, 7.472 calculated
Hardness: 5 to 5½
Streak: Greyish black
Colour: Steel grey to silver white
Common impurities: Bi
Environments:

Pegmatites
Metamorphic environments
Hydrothermal environments

Löllingite occurs in mesothermal deposits associated with other suphides and calcite gangue; it is also found in pegmatites (Webmin). Associated minerals include skutterudite, bismuth, nickeline, nickelskutterudite, siderite and calcite (HOM).

Localities

At Johanngeorgenstadt, Erzgebirgskreis, Saxony, Germany, löllingite was first identified from bismuth - cobalt - nickel veins during the final mining period of 1945–1958, as tiny, star-shaped crystals with collomorphic (crystallised from colloids) pitchblende. A specimen consisting of löllingite, safflorite, pitchblende and dyscrasite was found at the 95-fathom level (MinRec 55.5.599).

At the Carrock Mine, Mungrisdale, Eden, Cumbria, England, UK, grey-black löllingite has been found with yellowish green scorodite on quartz (AESS).
Löllingite from the Carrock Mine - Image

At the Emmons pegmatite, Greenwood, Oxford county, Maine, USA, löllingite forms masses to 15 cm across. Rare crude crystals occur in massive rhodochrosite. The Emmons pegmatite is an example of a highly evolved boron-lithium-cesium-tantalum enriched pegmatite (R&M 94.6.511).

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