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| Ankangite
is named for its discovery in the Ankang Prefecture, Shaanxi Province, China
(at the Shiti Mine, Hanbin District).
| Discovered
in 1986; IMA
status:
Not Valid (IMA Discredited 2012) |
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Chemistry
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Chemical
Formula: |
Ba(Ti,V3+,Cr3+)8O16
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Barium
Titanium Vanadium Chromium Oxide |
Molecular
Weight: |
803.05 gm
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Composition: |
Barium |
18.81 % |
Ba |
21.00 % |
BaO |
|
Titanium |
32.79 % |
Ti |
54.71 % |
TiO2 |
|
Vanadium |
15.22 % |
V |
22.40 % |
V2O3 |
|
Chromium |
1.29 % |
Cr |
1.89 % |
Cr2O3 |
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Oxygen |
31.88 % |
O |
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|
|
100.00 % |
|
100.00 % |
= TOTAL OXIDE |
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Classification
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Mineral
Classification: |
Oxides
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Hey's CIM Ref.:
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7.9.29
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7 : Oxides and Hydroxides
9 : Oxides of Ti
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Related
to: |
An
H2O-free variety of Mannardite.
Hollandite Supergroup;
Priderite
Group.
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Members
of Group: |
Priderite
Group: Henrymeyerite,
Mannardite, Priderite, Redledgeite
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Varieties: |
None
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Synonyms: |
ICSD 68631,
IMA1986-026, PDF 41-1427
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Crystal
Data
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Crystallography:
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Tetragonal - Dipyramidal
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Crystal
Habit:
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Crystals,
euhedral to subhedral, prismatic, with {100} and {110},
to 1 mm.
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Twinning:
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None
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Physical
Properties
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Cleavage: |
Interrupted elongation,
possibly a parting
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Fracture: |
Irregular/Uneven
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Tenacity:
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Brittle
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Moh's
Hardness: |
Vickers: VHN100=874 kg/mm2
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Density:
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4.44 (g/cm3)
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Luminescence:
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None
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Radioactivity:
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Not
Radioactive
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Optical
Properties
|
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Color: |
Black;
in reflected light, light rose-reddish gray
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Transparency: |
Opaque
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Luster: |
Vitreous
to adamantine |
Bireflectance: |
R1–R2:
(589) 12.8–20.1
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Birefringence: |
n/a |
Dispersion: |
n/a |
Pleochroism: |
O = pinkish grey, E = light pink, Orientation: E = c
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Anisotropism: |
Bireflectance:
Weak to distinct. Color
in
reflected light, light rose-reddish gray.
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Occurances
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Geological
Setting: |
In
a quartz vein.
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Common
Associations: |
Barite,
Barytocalcite, Roscoelite, Diopside
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Common
Impurities: |
n/a
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Type
Locality: |
Shiti Mine, Hanbin District, Ankang Prefecture, Shaanxi Province, China
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Year
Discovered: |
1986
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View
mineral photos: |
Ankangite
Mineral Photos and Locations |
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More
Information
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|
Mindat.org
Webmineral.com
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Ankangite
is named for its discovery in the Ankang Prefecture, Shaanxi Province, China
(at the Shiti Mine, Hanbin District).
Ankangite is a rare Barium
Titanium Vanadium Chromium Oxide mineral that can be
found as very interesting and attractive radiating
acicular "urchin looking" inclusions in Quartz
crystals. Quartz crystals with these rare, radiating
Ankangite inclusions have been found at
Morro Hill near the village of Tomás Gonzaga, Curvelo,
Minas Gerais, Brazil. All other locations produce lustrous,
black, prismatic Ankangite crystals that have grown
on the surfaces of host Quartz not as inclusions within
the Quartz. Ankangite was discovered in 1986 but was
discredited as a distinct mineral species in 2012 by
the IMA as it corresponds to an H2O-free variety of Mannardite.
Locations
for Ankangite: at the type locality at the Shiti Mine, Hanbin District, Ankang Prefecture, Shaanxi Province, China.
In Brazil as beautiful inclusions in Quartz crystals
at Morro Hill near the village of Tomás Gonzaga, Curvelo,
Minas Gerais. In Italy at Monte Arsiccio Mine, Sant'Anna di Stazzema, Stazzema, Apuan Alps, Lucca Province, Tuscany.
In Russia at the Pereval Marble Quarry, Slyudyanka (Sludyanka), Lake Baikal area, Irkutskaya Oblast', Prebaikalia (Pribaikal'e), Eastern-Siberian Region;
and at Vuonnemiok River Valley, Khibiny Massif, Kola Peninsula, Murmanskaja Oblast', Northern Region, Russia.
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