Artinite

artinite

hydromagnesite

pyroaurite

brucite

Images

Formula: Mg2(CO3)(OH)2.3H2O
Hydrated carbonate containing hydroxyl
Crystal System: Monoclinic
Specific gravity: 2.01 to 2.03 measured, 2.047 calculated
Hardness: 2½
Streak: White
Colour: White; colourless in transmitted light
Solubility: Readily soluble with effervescence in cold acids
Environments

Metamorphic environments
Hydrothermal environments

Artinite is a low-temperature mineral in weathered or altered ultramafic rocks, typically serpentinites, likely occurring worldwide. Associated minerals include brucite, hydromagnesite, pyroaurite, chrysotile, aragonite, calcite, dolomite and magnesite (HOM).

Localities

At the type locality, Dossi di Franscia, Campo Franscia, Lanzada, Sondrio Province, Lombardy, Italy, artinite occurs as acicular crystals forming cross-fibre veinlets, botyroidal crusts, and spherical or bow-tie aggregates of divergent crystals. It is a low-temperature mineral in weathered or altered ultramafic rocks, typically serpentinites. Associated Minerals include brucite, hydromagnesite, pyroaurite, chrysotile, aragonite, calcite, dolomite and magnesite (Mindat).

At Luning, Fitting Mining District, Mineral county, Nevada, USA, veins cutting massive brucite are made up of hydromagnesite, granular brucite and acicular artinite. (AM 31.365-369).

At the Spring Street Artinite occurrence, Staten Island (Richmond county), New York City, New York, USA the serpentinites exposure produced fine specimens of artinite and hydromagnesite; the largest specimens exceeded 45 cm across. The artinite formed fine white coatings and hemispherical sprays of crystals, to 25 mm long, in narrow seams running through a greenish serpentinite matrix. Smaller hemispherical crystal aggregates to 2 mm across of white hydromagnesite and hexagonal bronze-coloured pyroaurite crystals to 1 mm are frequently associated with the artinite. Octahedral microcrystals of magnetite are found throughout the deposit. Both the artinite and the hydromagnesite fluoresce white under UV. Remnants of the serpentinite knoll still exist, but the area is fenced and closed to collecting (R&M 84.3.220).

At the Victory Diner locality, Staten Island (Richmond county), New York City, New York, USA, artinite and hydromagnesite were found in a serpentinites outcrop, together with brucite, aragonite, calcite and other minerals (R&M 43.9.643-647).

At the Belvidere Mountain Quarries, Lowell & Eden, Orleans & Lamoille counties, Vermont, USA, artinite occured as white, radially fibrous, botryoidal crusts associated with pyroaurite along slip planes in serpentinites. A further report mentions artinite occurring in white mats of bladed crystals to 1 mm, intergrown with massive diopside, pyrite and grossular (R&M 90-6.527).

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