Ganophyllite

phyllosilicate

astrophyllite

Formula: (K,Na)xMn2+6(Si,Al)10O24(OH)4.nH2O (x=1-2; n=7-11)
Phyllosilicate (sheet silicate), ganophyllite group
Specific gravity: 2.84 to 2.88
Hardness: 4 to 4½
Streak: Brownish yellow
Colour: Brownish yellow, cinnamon-brown
Solubility: Gelatinises in acids
Environments:

Metamorphic environments

Ganophyllite occurs in manganese-rich portions of metamorphosed zinc-manganese mineral deposits.

At Mont Saint-Hilaire, Quebec, Canada, ganophyllite occurs with astrophyllite and labuntsovite (Dana).

At the Molinello mine, Italy, ganophyllite is associated with parsettensite and caryopilite (HOM).

At Harstigen mine, Sweden, ganophyllite is associated with calcite, rhodonite, caryopilite, baryte, lead, garnet, manganoan biotite and pyrophanite (HOM).

At Franklin, New Jersey, USA, ganophyllite is associated with rhodonite, willemite, bustamite, axinite, clinohedrite, datolite, roeblingite and charlesite (HOM).

Common impurities: Fe,Zn,Pb,Ca,Ba

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