Redledgeite

redledgeite

mannardite

chromite

knorringite

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Formula: Ba(Ti6Cr3+2)O16
Oxide, priderite group, hollandite supergroup, barium- and titanium- bearing mineral
Crystal System: Tetragonal
Specific gravity: 3.72 measured, 4.413 calculated
Hardness: 6 to 7
Streak: White, grey
Colour: Green, yellow, black
Environments

Plutonic igneous environments

Redledgeite has been compared with mannardite from the Rough claims, Kechika River, Sifton Pass, Liard Mining Division, British Columbia, Canada. Extensive tests indicated that redledgeite is isostructural with, but more fully ordered than, mannardite, and redledgeite is the chromium analog of mannardite (CM 24.55-66).

Localities

At the type locality, the Red Ledge mine, Washington, Washington Mining District, Nevada County, California, USA, redledgeite is associated with chromite and knorringite (Mindat).

A re-examination of holotype redledgeite has shown it to be intimately and finely intergrown with light pink crystals of chromium-bearing clinochlore. A second specimen of redledgeite, recently collected from the type locality shows small black elongate grains of redledgeite in a groundmass of translucent, light green, extremely fine-grained acicular tetragonal crystals. These minute needles are 0.5 microns thick and cling with great tenacity to the larger crystals of redledgeite (CM 24.55-66).

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