:Locality: Torrecillas Mine, Salar Grande, Iquique, Tarapacá Region, Chile Size: 3.7 × 3 × 1.8 cm Description: Really interesting sample of canutite, a rare sodium and manganese arsenate, formed by several groups of brilliant, transparent and brown color crystal aggregates. They are accompanied by light blue lavendulan, cubic crystals of halite and pinkish magnesiokoritnigite. Canutite and magnesiokoritnigite have the Type Locality in this mine (rather number of small prospects), close to magnesiocanutite that is visually not distinguishable from canutite. A complete and representative specimen. — Photo: Joan Rosell , from rosellminerals.com · CC BY-SA 4.0
Magnesiokoritnigite
Magnesiokoritnigite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Mg(AsO₃OH)·H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Koritnigite structural group.
Key properties: Mohs hardness 3; specific gravity 2.95; White streak; Vitreous luster; optically biaxial.
IMA symbol Mkor, IMA status: approved, named in 2013.
Found as a secondary mineral derived from the oxidation of native arsenic and other As-bearing primary phases, followed by later alteration by saline fluids derived from evaporating meteoric water under hyperarid conditions.
It is found associated with Anhydrite, chudobaite, halite, lavendulan, quartz, scorodite.
As the magnesium-analogue of koritnigite.