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Formula: Ba(Ti6V3+2)O16
Oxide, priderite group,
hollandite supergroup,
barium-, titanium- and
vanadium- bearing mineral
Crystal System: Tetragonal
Specific gravity: 4.12 measured, 4.28 calculated
Hardness: 7
Streak: White to greyish white
Colour: Jet-black
Environments
Sedimentary environments
Hydrothermal environments
Localities
There are two co-type localities,
the Rough claims, Kechika River, Sifton Pass, Liard Mining Division, British Columbia, Canada
and
the Shiti Mine, Hanbin District, Ankang, Shaanxi, China.
At the Gacun Mine, Maqiong, Baiyü County, Garzê Autonomous Prefecture, Sichuan, China, mannardite occurs in
a silver-bearing polymetallic deposit
(HOM).
At the Rough claims, Kechika River, Sifton Pass, Liard Mining Division, British Columbia, Canada, mannardite
occurs in narrow quartz-carbonate veins that cut a Devonian (419.2 to
358.9 million years ago) shale and
siltstone sequence. The veins containing mannardite are
apparently nearly vertical and appear to post-date the folding of the sedimentary strata.
Three distinct types of mannardite-bearing vein material have been collected to date.
Type A material, which contains the largest crystals of mannardite, is unweathered, massive to somewhat vuggy,
milky vein quartz in which cavities have been completely infilled with
crystalline patches up to 1 cm in diameter of cream-coloured
barytocalcite and elongate flattened crystals of greenish grey
norsethite. The carbonates postdate the mannardite. A generation
of small euhedral clear crystals of quartz lines the vugs, and
mannardite, as euhedral terminated crystals, is found growing within and upon these.
Type-B material is the weathered equivalent of type A, in which almost all the
barytocalcite has been altered to form pockets of very fine-grained
powdery white baryte. Norsethite is
very rare, and the quartz also contains a few crystals of
sulvanite as bronzy black, tarnished cubes to 5 mm in size. In type-B
material, the mannardite usually forms radial clumps of terminated crystals in the
quartz; most crystals are about 0.2 x 0.2 x 1 mm3. In general,
mannardite appears to be contemporaneous with the sulvanite but
earlier than the carbonates and most of the quartz.
Type-C material consists of late-stage fracture fillings of columnar quartz
centrally cross-cutting type-B veins. Mannardite occurs as elongate needles along the columnar
quartz grainboundaries and is particularly plentiful as small isolated
crystals at and near the edges of the veins. There has been minor infilling of tubular voids between the
quartz columns with
barytocalcite; no other species were observed.
Mannardite occurs as shiny jet-black elongate prismatic crystals, with an adamantine lustre; the crystals are
deeply striated parallel to their elongation. The streak is white; however, depending on the pressure used and the
direction in which the streak is taken, it may appear greyish as a result of the presence of a host of tiny black
needles
(CM 24.1.55-66).
Image
At the Brunswick No. 12 mine, Bathurst Mining Camp, Bathurst Parish, Gloucester county, New Brunswick, Canada,
mannardite occurs in an orebody in faulted metasediments and iron formation, in association with
edingtonite, harmotome,
barytocalcite, siderite,
sphalerite and quartz
(HOM).
The Shiti Mine, Hanbin District, Ankang, Shaanxi, China, is a baryte mine;
it is a co-type locality for mannardite and the type locality for
hanjiangite
(Mindat).
At the Star Mine, Theunissen kimberlite field, Theunissen, Masilonyana Local Municipality, Lejweleputswa District
Municipality, Free State, South Africa, mannardite has been found in
kimberlite
(HOM).
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