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| Tarbuttite
was named to honor Percy Coventry Tarbutt, Director
of the Broken Hill Exploration Company, who collected
some of the first specimens at Broken Hill (now Kabwe),
Zambia.
| Discovered
in 1907.
IMA
status: Valid (pre-IMA; Grandfathered) |
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Chemistry
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Chemical
Formula: |
Zn2(PO4)(OH) |
|
Zinc Phosphate Hydroxide
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Molecular
Weight: |
242.76 gm
|
Composition: |
Zinc |
53.87 % |
Zn |
67.05 % |
ZnO |
|
Phosphorus |
12.76 % |
P |
29.24 % |
P2O5 |
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Hydrogen |
0.42 % |
H |
3.71 % |
H2O |
|
Oxygen |
32.95 % |
O |
|
|
|
|
100.00 % |
|
100.00 % |
= TOTAL OXIDE |
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Classification
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Mineral
Classification: |
Phosphates
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Strunz 8th
Ed. ID:
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7/B.06-50
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Nickel-Strunz 10th
Ed. ID:
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8.BB.35
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8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H2O
B : With only medium-sized cations, (OH, etc.):RO4 about 1:1
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Related
to: |
Olivenite
Group. Tarbuttite Group. May form pseudomorphs after Smithsonite, Descloizite and possibly also Hemimorphite. May alter to Parahopeite.
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Crystal
Data
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Crystallography:
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Triclinic - Pinacoidal
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Crystal
Habit:
|
Crystals
typically equant to short prismatic, complex, with many
forms, to 2 cm; in sheaflike or saddle-shaped aggregates;
as crusts.
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Twinning:
|
None
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Physical
Properties
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Cleavage: |
Perfect
on {001}
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Fracture: |
Uneven/Irregular
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Tenacity:
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Brittle
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Moh's
Hardness: |
3.5
- 4.0
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Density:
|
4.12 (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: |
Colorless,
pale yellow, may be brown, red, or green; colorless
in transmitted light.
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Transparency: |
Translucent to
Transparent
|
Luster: |
Vitreous,
Pearly on cleavages
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Refractive
Index: |
1.659
- 1.713 Biaxial ( - )
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Birefringence: |
0.0530
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Dispersion: |
Weak
to Strong
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Pleochroism: |
Very
Strong
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Occurances
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Geological
Setting: |
An
uncommon secondary mineral in the oxidized zone of zinc-bearing
deposits. |
Common
Associations: |
Hopeite,
Hemimorphite, Smithsonite, Parahopeite, Hydrozincite,
Scholzite, Cerussite, Pyromorphite, Descloizite, Vanadinite,
“Limonite” |
Type
Locality: |
Kabwe Mine (Broken Hill Mine), Kabwe (Broken Hill), Central Province, Zambia
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Year
Discovered: |
1907
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View
mineral photos: |
Tarbuttite
Mineral Photos and Locations |
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More
Information
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|
|
Mindat.org
Webmineral.com
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Tarbuttite
is a rare zinc phosphate mineral that belongs to the
Olivenite
Group of minerals that also includes Adamite.
Tarbuttite is typically rather unattractive, even ugly
by mineral specimen standards. It has been referred
to as a bat-poop mineral since it often forms in ancient
caves under layers of mineral-rich bat guano deposited
over tens of thousands of years. However, specimens
from the Skorpion Mine in the Rosh Pinah, Lüderitz District, Karas Region
of Namibia are different. Crystals from a new find
there in 2007 are transparent, pastel green and gemmy.
Tarbuttite
has been found at these localities: the type locality
at Kabwe (Broken Hill), Zambia. In the Lueca vanadium
mines, Angola. From the Kef Semmah mine, near Sétif,
Algeria. In Australia, on Reaphook Hill, near Blinman,
Flinders Ranges, South Australia; at Broken Hill, New
South Wales. In the Hudson Bay mine, Salmo, British
Columbia, Canada. At an undefined locality in Guangdong
Province, China. The best crystals are from the Skorpion
Mine, Rosh Pinah, Lüderitz District, Karas Region,
Namibia.
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