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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
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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