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Formula: Ba0.5Fe3+4(AsO4)3(OH)4.5H2O
Hydrated arsenate containing hydroxyl,
pharmacosiderite group
Crystal System: Tetragonal
Specific gravity: 3.05 measured, 3.07 calculated
Hardness: 2½
Colour: Brown, yellow, reddish brown, green, bluish
Solubility: Readily soluble in warm 1:1 hydrochloric acid (Dana)
Environments
Localities
At Sunny Corner, New South Wales, Australia, occasionally bariopharmacosiderite forms in thin crusts in voids
in beudantite - scorodite ore.
Layers of goethite between separate generations of
bariopharmacosiderite indicate alternating
goethite and bariopharmacosiderite mineralising events, after the
beudantite and scorodite had
formed. Minor
secondary baryte is
also found in
association with bariopharmacosiderite and tiny crystals of bariopharmacosiderite associated with
native sulphur have been in voids after
arsenopyrite in rock
on a mine dump
(AJM 17.1.48).
At the type locality, the Clara mine, Oberwolfach, Ortenaukreis, Freiburg Region, Baden-Württemberg, Germany,
bariopharmacosiderite
occurs on limonite and baryte
(Dana).
At Burdell Gill, Caldbeck Fells, Cumbria, England, UK, bariopharmacosiderite is associated with
rhodochrosite, and
vivianite is often associated
with corroded bariopharmacosiderite
(JRS 8(1).1-9)
At Roughton Gill, Caldbeck Fells, Cumbria, England, UK, bariopharmacosiderite occurs in thin fractures in
iron and manganese oxide rich
wallrock and is often partially coated by iron oxide. Crystals and occasional
anhedral masses of
bariopharmacosiderite with beudantite and
carminite have been collected from scree blocks near to the main vein
exposure
(JRS 11.7).
At Short Grain, Caldbeck Fells, Cumbria, England, UK, minute crystals of bariopharmacosiderite occur with
arseniosiderite,
beudantite and
mimetite in quartz -
baryte veinstone.
Primary baryte is
likely to have provided the barium ions required for
bariopharmacosiderite to crystallise
(JRS 12.51).
At the Tintic Mining District, Juab County, Utah, USA, bariopharmacosiderite has been found at the Centennial
Eureka mine both as single cubic crystals and as druses on quartz. It occurs
associated with arseniosiderite,
azurite, beudantite,
clinoclase, scorodite and
tyrolite.
At the North Star mine, it usually occurs on quartz or
goethite, with associations of
baryte, enargite,
mixite, olivenite,
pyrite and volborthite.
Individual cubic crystals measure only a few hundred microns, but druses of these crystals may cover up to a few
square centimeters on matrix.
Single cubes of bariopharmacosiderite isolated on quartz also have
been found at the North Star mine
(MinRec 55.2.183-184).
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