Minerals identify

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Gersdorffite

Mineral

Gersdorffite is a nickel mineral with formula NiAsS. It crystallizes in the isometric system showing diploidal symmetry. It occurs as euhedral to massive opaque, metallic grey-black to silver white forms. Gersdorffite belongs to a solid solution series with cobaltite freely substitutes also leading to ullmannite , NiSbS. It has a Mohs hardness of 5.9 to 6.33.

Gersdorffite has three crystallisation forms: Gersdorffite-P213 (NiAsS), Gersdorffite-Pa3 (Ni(As,S)2) and Gersdorffite-Pca21 (NiAsS). Gersdorffite occurs as a hydrothermal mineral along with other nickel sulfides. Associated minerals include nickeline , nickel-skutterudite , cobaltite, ullmannite, maucherite, platinum-group minerals, millerite, and chalcopyrite.

Gersdorffite was first described in 1843 and named for Johann von Gersdorff (1781–1849), owner of the nickel mine at Schladming, Austria the type locality.

Identification

Color of mineral

Grey
Silver
White

Mohs scale ( mineral hardness )

5
5.5

The streak

Black

Crystal ( diaphaneity )

P213polytype:cu