:Locality: Great Fissure Eruption, Tolbachik Volcano, Far Eastern Region, Russian Federation Size: 0.2 × 0.2 × 0.2 cm Description: Two small (0.25 and 0.20 mm) aggregates of alarsite crystals from this incredible volcano with more than 100 Type Locality species. Alarsite is a extremelly rare aluminum arsenate AlAsO4. Analyzed. The mineral occurs in the fumarolic deposits of the Great Tolbachik fissure extrusion, in the SE of the Kamchatka Peninsula, and it is associated with very rare species like langbeinite, fedotovite, kluychevskite, lammerite, etc. — Photo: Joan Rosell , from rosellminerals.com · CC BY-SA 4.0
Alarsite
An aluminium arsenate named simply for its composition, forming brittle trigonal grains.
Intro adapted from Wikipedia (CC BY-SA).
Alarsite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Al(AsO₄).
It crystallizes in the hexagonal crystal system (space group P3_121). It is a member of the Quartz structural group.
Key properties: specific gravity 3.32; White streak; Vitreous luster; optically uniaxial.
IMA symbol Ars, IMA status: approved, named in 1993.
A fumarolic mineral.
It is found associated with Fedotovite, klyuchevskite, lammerite, nabokoite, atlasovite, langbeinite, hematite, tenorite.
The name refers to ALuminum and ARSenic in the composition.