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Formula: PbCu(VO4)(OH)
Anhydrous vanadate containing hydroxyl,
adelite-descloizite group
Varieties
Duhamelite is a calcium and bismuth bearing variety of mottramite
Properties
Crystal System: Orthorhombic
Specific gravity: 5.9 measured, 6.187 calculated
Hardness: 3 to 3½
Streak: Yellowish
Colour: Grass-green, olive-green, yellow-green, siskin-green, blackish brown, nearly black
Solubility: Readily soluble in acids
Environments
Mottramite is a secondary mineral associated with
descloizite in oxidised zones,
especially in sandstone.
Localities
At Tsumeb, Namibia, mottramite pseudomorphs after
cerussite, after calcite, after
wulfenite on lead-rich calcite and
after copper with calcite have been found
(KL p200-203).
At Mottram St Andrew, Cheshire, England, UK, mottramite occurs as an encrustation on
sandstone, associated with
duftite, later mimetite and
pyromorphite and plumbogummite
(RES pps 58-60).
At Arm O'Grain, Caldbeck, Cumbria, England, UK, mottramite has been found on a
quartz matrix
(AESS).
At Peldar Tor quarry, Spring Hill, Whitwick, Leicestershire, England, UK, mottramite crystals have been found on a
calcite, dolomite and
quartz matrix
(RES p201).
At Pim Hill mine, Harmer Hill, Shropshire, England, UK, mottramite occurs on
sandstone
(RES p292).
At Judkins quarry, Nuneaton, Warwickshire, England, UK, mottramite has been found with
baryte, coating calcite
(RES p324).
At the Total Wreck mine, Cochise county, Arizona, USA, pseudomorphs of
mottramite after
wulfenite have been found (R&M 94.2.169).
At the Kabwe mine, Central Province, Zambia, mottramite has been reported in
dolomite, with inclusions of
rosasite (R&M 94.2.130).
Common impurities: Zn
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