Charoite

charoite

canasite

tinaksite

steacyite

Images

Formula: (K,Sr,Ba,Mn)15-16(Ca,Na)32[Si70(O,OH)180](OH,F)4.nH2O
Inosilicate (chain silicate), strontium-, barium- and manganese- bearing mineral
Crystal System: Monoclinic
Specific gravity: 2.54 measured, 2.77 calculated
Hardness: 5 to 6
Streak: White
Colour: Violet to deep lilac, whitish grey to brown
Luminescence: Weakly fluorescent under UV, wave pale blue, long wavepale blue. Orange cathodeluminescent (Webmin)
Solubility: Insoluble in acids
Common impurities: Al,Fe
Environments

Metamorphic environments

Charoite occurs in K-feldspar metasomatites. Common associates include aegirine, canasite, steacyite and tinaksite (Mindat).

Localities

At the type locality, the Murunskii Massif, Chara and Tokko Rivers Confluence, Aldan Shield, Russia, charoite occurs in K-feldspar metasomatites at the contact of nepheline and aegirine syenites with limestones. Associated minerals include canasite and tinaksite (HOM).
The rocks formed between 200 and 250oC and were enriched with potassium at the contact of the massif with limestone (Webmin).

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