Artinite

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Artinite
Artinite-206168.jpg
Artinite from New Idria District, California
General
Category Carbonate mineral
Formula
(repeating unit)
Mg2(OH)2CO3·3H2O
Strunz classification 05.DA.10
Crystal system Monoclinic
Unit cell a = 16.56 Å, b = 3.15 Å, c = 6.22 Å; β = 99.15°; Z=1
Identification
Color White
Crystal habit Acicular crystals, fibrous veinlets, botyroidal crusts, and spherical aggregates
Crystal symmetry Monoclinic Space group: C 2/m
Cleavage On {100} perfect; on {001} good.
Mohs scale hardness 2.5
Luster Vitreous, silky
Streak White
Diaphaneity Transparent
Specific gravity 2.01 - 2.03
Optical properties Biaxial (-)
Refractive index nα = 1.488 - 1.489 nβ = 1.533 - 1.534 nγ = 1.556 - 1.557
Birefringence δ = 0.068
References [1][2][3]

Artinite is a hydrated magnesium carbonate mineral with formula: Mg2(CO3)(OH)2·3H2O. It forms white silky monoclinic prismatic crystals that are often in radial arrays or encrustations. It has a Mohs hardness of 2.5 and a specific gravity of 2.

It occurs in low-temperature hydrothermal veins and in serpentinized ultramafic rocks. Associated minerals include brucite, hydromagnesite, pyroaurite, chrysotile, aragonite, calcite, dolomite and magnesite.[1]

It was first reported in 1902 in Lombardy, Italy. It was named for Italian mineralogist, Ettore Artini (1866–1928).[2]

Artinite sometimes forms balls of radiating, fibrous crystals. Specimen from New Idria district, California US. Size: 9.2 x 5.2 x 1.5 cm.

References[edit]