Aliettite | |
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General | |
Category | Phyllosilicates |
IMA symbol | Ali [1] |
Strunz classification | 9.EC.60 |
Crystal system |
Hexagonal Unknown space group |
Unit cell | a = 5.216, c = 24.6 [Å]; Z = 1 |
Identification | |
Color | Colorless, pale yellow or green. |
Crystal habit | Platy |
Mohs scale hardness | 1–2 |
Luster | Earthy (dull) |
Streak | White |
Diaphaneity | Translucent |
Refractive index | 1.558–1.567 |
References | [2] [3] [4] [5] |
Aliettite is a complex phyllosilicate mineral of the smectite group with a formula of ( Ca0.2 Mg6( Si, Al)8 O20( OH)4·4 H2O) [2] or [Mg3Si4O10(OH)2](Ca0.5,Na)0.33(Al,Mg,Fe2+)2−3(Si,Al)4O10(OH)2·n(H2O). [3] [4]
It is a soft, colorless to pale yellow or green earthy mineral which crystallizes in the monoclinic system as minute tabular to platy crystals. [2]
It was first described in 1968 for an occurrence in Monte Chiaro, Albareto, Parma Province, Emilia-Romagna, Italy and named for the Italian mineralogist Andrea Alietti (born 1923). [2]
It occurs in serpentinized ophiolites and their residual soil. It also occurs in altered dolomite. Associated minerals include talc, chlorite, serpentine and calcite. [4] In addition to the type locality in Italy it has been reported from Kinshasa, Katanga; [4] the Chelyabinsk Oblast of the southern Urals and the Turii alkaline Massif of the Kola Peninsula in Russia; the Zirabulak Mountains of Uzbekistan; and the Goldstrike Mine of Eureka County, Nevada, US. [2]