Fluorcalcioroméite

fluorcalcioromeite

braunite

wallkilldellite-(Mn)

roméite

Images

Formula: (Ca,Na)2Sb5+2O6F
Oxide, roméite group, pyrochlore supergroup, antimony-bearing mineral, forms a series with oxyplumboroméite and with roméite
Crystal System: Isometric
Specific gravity: 5.113 calculated
Hardness: 5½
Streak: White
Colour: Yellow to orange
Luminescence: Non-fluorescent under UV
Environments

Sedimentary environments
Metamorphic environments

Localities

At the type locality, the Starlera Mine, Starlera Valley, Ferrera, Viamala Region, Grisons, Switzerland, fluorcalcioroméite occurs intimately associated with braunite, hematite, calcite, quartz and, rarely, wallkilldellite. It occurs as euhedral octahedra, untwinned, from 0.1 to 1 mm in size. The crystals are yellow to orange and translucent with a vitreous to resinous lustre (MM 77.467-473).
The geological setting is in dolomitic marble (Mindat).

Fluorcalcioromeite from the Starlera Mine - Image

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