Naalasite

naalasite

magnesiokoritnigite

juansilvaite

anhydrite

Images

Formula: NaAl(As⁵⁺O₃OH)₂.H₂O
Hydrated hydrogen arsenate
Crystal System: Trigonal
Specific gravity: 3.19 measured, 3.235 calculated
Hardness: 3½
Colour: Light to medium pink
Luminescence: No fluorescence under long wave or short wave UV
Solubility: Dissolves slowly in dilute hydrochloric acid at room temperature
Environments

Hydrothermal environments

Naalasite is a new mineral, approved in 2023 and to date (May 2024) reported only from the type locality.

Localities

At the type locality, the Torrecillas mine, Iquique Province, Tarapacá, Chile, naalasite is a secondary alteration phase associated with anhydrite, juansilvaite, magnesiokoritnigite and a lavendulan-like phase. Naalasite occurs in tightly intergrown aggregates and druses of equant light to medium pink and transparent crystals with a vitreous lustre (MM 88.2.155-161).

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