Category Cyclosilicate Crystal system Tetragonal | Strunz classification 9.CH.10 Space group P4/mcc | |
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Formula(repeating unit) Kvariable(Ca,Na)2(Th,U)Si8O20 Crystal class Ditetragonal dipyramidal (4/mmm)H-M symbol: (4/m 2/m 2/m) | ||
Steacyite is a complex silicate mineral containing thorium and uranium; formula Kvariable(Ca,Na)2(Th,U)Si8O20. It forms small brown or yellow green crystals, often cruciform twinned crystals. It is radioactive. It was discovered at Mont-Saint-Hilaire, Quebec in 1982 and is named after Harold Robert Steacy (1923–2012), mineralogist.
References
Steacyite Wikipedia(Text) CC BY-SA