Chondrodite

chondrodite

antigorite

magnetite

iowaite

Images

Formula: Mg5(SiO4)2F2
Nesosilicate (insular SiO4 groups)
Specific gravity: 3.1 to 3.2
Hardness: 6 - 6½
Streak: White
Colour: Yellow, brown, red, rarely green
Solubility: Slightly soluble in hydrochloric acid
Common impurities: Ti,Al,Mn
Environments:

Carbonatites (rarely)
Metamorphic environments (typically)

Chondrodite occurs in contact or regionally metamorphosed dolomitic limestone or dolostone, associated with diopside, spinel and phlogopite.
It also may be found in serpentinite associated with magnetite, and in skarn associated with wollastonite, forsterite and monticellite.

Localities

At Palabora, Limpopo Province, South Africa, chondrodite occurs atypically in carbonatite, associated with calcite, magnetite, clinochlore and less commonly with iowaite (R&M.92.5.437).

Amity, Town of Warwick, Orange county, New York, USA, is an area of granite intrusions into marble and associated gneiss. The marble is mostly composed of white crystalline calcite that often has small flakes or spheres of graphite and phlogopite. Chondrodite is a common mineral, forming as agglomerations of dark brownish red crystals or crusty coatings on white marble; it is often associated with spinel (R&M 96.5.435).

At the Tilly Foster mine, Brewster, Putnam county, New York, USA, antigorite pseudomorphs after chondrodite have been found with magnetite on kaolinite (KL p233).

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