Artinite crystals on the matrix (6.5 × 4.0 × 2.5 cm) from Atlas mine Nº1, San Benito, California, USA — Photo: Ivar Leidus · CC BY-SA 4.0
Artinite
A hydrated magnesium carbonate forming white silky prisms, often in radial clusters or crusts.
Intro adapted from Wikipedia (CC BY-SA).
Artinite is an IMA-recognized mineral species in the carbonate class, with the chemical formula Mg₂(CO₃)(OH)₂·3H₂O.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Artinite structural group.
Key properties: Mohs hardness 2.5; specific gravity 2.02–2.03; White streak; Vitreous, silky to satiny in aggregates luster; refractive index 1.526; optically biaxial.
IMA symbol Art, grandfathered status — known before the IMA’s founding, named in 1902.
A low-temperature mineral in weathered or altered ultramafic rocks, typically serpentinites, likely occurring worldwide.
It is found associated with Brucite, hydromagnesite, pyroaurite, chrysotile, aragonite, calcite, dolomite, magnesite.
The mineral was named to honor Professor Ettore Artini (1866–1928), Italian mineralogist, University of Milan and Director of the Natural History Museum, Milan, Italy.