Artinite
Artinite is a hydrated basic 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.
| Artinite | |
|---|---|
|  Artinite from New Idria District, California | |
| General | |
| Category | Carbonate mineral | 
| Formula (repeating unit) | Mg2(CO3)(OH)2·3H2O | 
| IMA symbol | Art[1] | 
| Strunz classification | 5.DA.10 | 
| Crystal system | Monoclinic | 
| Crystal class | Prismatic (2/m) (same H-M symbol) | 
| Space group | C2/m | 
| Unit cell | a = 16.56, b = 3.15 c = 6.22 [Å]; β = 99.15°; Z = 2 | 
| Identification | |
| Color | White | 
| Crystal habit | Acicular crystals, fibrous veinlets, botryoidal crusts, and spherical aggregates | 
| 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 | [2][3][4] | 
It occurs in low-temperature hydrothermal veins and in serpentinized ultramafic rocks. Associated minerals include brucite, hydromagnesite, pyroaurite, chrysotile, aragonite, calcite, dolomite and magnesite.[2]
It was first reported in 1902 in Lombardy, Italy. It was named for Italian mineralogist, Ettore Artini (1866–1928).[3]

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
    
- Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- Handbook of Mineralogy
- Artinite on Mindat.org
- Artinite on Webmineral

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