Mottramite

Mottramite Ojuela Mine, Mapimi, Mun. de Mapimi, Durango, Mexico Size: 13.0 x 11.0 x 8.0 cm (cabinet) © danweinrich

Chemical Formula: PbCu(VO4)(OH)
Locality: Mottram, St. Andrews, Cheshire, England.
Name Origin: Named for the locality.

Mottramite is an orthorhombic mineral, PbCu(VO4)(OH), at the copper end of the descloizite group. It was formerly called cuprodescloizite or psittacinite (this mineral characterized in 1868 by Frederick Augustus Genth).

History

Discovery date : 1876
Town of Origin: MOTTRAM, ST. ANDREW’S, CHESHIRE
Country of Origin : ANGLETERRE

Optical properties

Optical and misc. Properties: Transparent to Opaque
Refractive Index: from 2,17 to 2,32
Axial angle 2V : ~73°

Physical Properties

Cleavage: None
Color:     Brown, Brown red, Brownish black, Green, Dark green.
Density: 5.9 – 6, Average = 5.95
Diaphaneity: Transparent to Opaque
Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals.
Hardness: 3.5 – Copper Penny
Luster: Greasy (Oily)
Streak: light brownish green

Photos:

Mottramite 5.2×3.6×2.3 cm Tsumeb Corp. Mine Tsumeb Namibia Copyright © David K. Joyce Minerals
Mottramite Ojuela Mine, Mapimi, Mun. de Mapimi, Durango, Mexico Size: 2.9 x 2.0 x 0.8 cm (thumbnail) © danweinrich
Cerussite on Mottramite Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia Cabinet, 9.4 x 6.3 x 5.3 cm © irocks