Fluor-schorl

Fluor-schorl Locality: Tennvatn pegmatite, Sørfold, Nordland, Norway Dimensions: 23 mm x 11 mm x 10 mm. Largest Crystal Size: 5 mm Description: One of the new members of the expanding tourmalinegroup. From rare-mineral dealer J.Hyrsl. Photo and collection Erik Vercammen — Photo: Erik Vercammen · CC BY 3.0

Fluor-schorl

Fluor-schorl is an IMA-recognized mineral species in the silicate class, with the chemical formula NaFe²⁺₃Al₆(Si₆O₁₈)(BO₃)₃(OH)₃F.

It crystallizes in the hexagonal crystal system (space group R3m). It is a member of the Tourmaline structural group.

Key properties: Mohs hardness 7; specific gravity 3.2; Bluish white streak; Vitreous luster; optically uniaxial.

IMA symbol Fsrl, IMA status: approved, named in 2010.

A pneumatolytic phase in association with tin mineralization (Zschorlau) and in high- temperature hydrothermal veins in granitic pegmatites (Grasstein).

It is found associated with Quartz, biotite, albite, orthoclase, schorl, apatite, beryl, cassiterite, “wolframite” (Zschorlau).

As the F-analogue of schorl.