Sharp metallic crystals of enneasartorite and hendekasartorite, two extremely rare thallium minerals from the Lengenbach quarry (IMA 2015-074 and IMA 2015-075, respectively, both announced in February 2016) grown on realgar. Both species have been analyzed by EDX by Dr. Topa of the NHM Wien, ref. HG076. Enneasartorite and hendekasartorite are two members of the sartorite group minerals. — Photo: David Hospital · CC BY-SA 4.0
Enneasartorite
An extremely rare thallium-lead-arsenic sulfosalt of the sartorite homologous series.
Intro adapted from Wikipedia (CC BY-SA).
Enneasartorite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Tl₆Pb₃₂As₇₀S₁₄₀.
It crystallizes in the monoclinic crystal system (space group P2_1/c). It is a member of the Sartorite structural group.
Key properties: Mohs hardness 3–3.5; specific gravity 5.1; Dark brown streak; Metallic. Anisotropism: Moderate to weak in brown-violet and deep green tints. Bireflectance: Weak luster.
IMA symbol Esat, IMA status: approved, named in 2015.
Found in dolostone.
It is found associated with Heptasartorite, rathite, baumhauerite.
The name refers to a member of the sartorite homologous series with a nine-fold superstructure.