May 28 2014
Stibiotantalite is a member of the Cervantite family. It was first discovered in Greenbushes tin placers of the Wodgina district in Western Australia.
It was named from the Latin for antimony - STIBIum - in its composition, and its relation to tantalite.
Properties of Stibiotantalite
The following are the key properties of Stibiotantalite:
- Cell Data
- Space Group: Pc21n (synthetic SbTaO4)
- a = 4.911
- b = 11.814
- c = 5.535
- Z = 4
- Crystal Data
- Orthorhombic
- Point Group: mm2
- Crystals: prismatic (roman numeral two ) || [010], flattened (roman numeral two ) || to [001], may be equant, to 12cm; {001} and {101} striated (roman numeral two ) || [010]
- Twinning: About [010] with composition plane {001}; polysynthetic
- X-ray Powder Pattern: 3.121 (100), 3.506 (38), 2.950 (34), 2.687 (22), 2.692 (21), 1.735 (19), 1.888 (17)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| Ta2O5 |
57.29 |
43.3 |
60.25 |
| Sb2O3 |
40.64 |
40.3 |
39.75 |
| Nb2O5 |
1.79 |
11.3 |
- |
| Bi2O3 |
0.30 |
3.8 |
- |
| SiO2 |
- |
0.1 |
- |
| CaO |
- |
0.1 |
- |
| Total |
100.02 |
98.9 |
100.00 |
- Optical Properties
- Optical Class: Biaxial (+)
- Orientation: X = a; Y = b; Z = c
- Dispersion: r < v, strong
- α = 2.374
- β = 2.404
- γ = 2.457
- 2V(meas.) = n.d
- 2V(calc.) = 75°5'
- Estimated Properties
| Electron density |
Bulk density (electron density) = 6.44 g/cm3
note: Specific gravity of Stibiotantalite = 7.57 g/cm3 |
| Photoelectric |
PEStibiotantalite = 711.98 barns/electron
U = PEStibiotantalite x ρElectron density = 4585.80 barns/cm3 |
| Fermion index |
Fermion index = 0.0001
Boson index = 0.9998 |
Radioactivity
|
Stibiotantalite is not radioactive
|
How to Identify Stibiotantalite
Stibiotantalite occurs in a range of colors, from brown to greenish-yellow, yellow, light yellow-brown, and dark brown. It has brittle fractures producing small, conchoidal fragments. The mineral is non-magnetic and non-fluorescent in nature. It has perfect cleavage, light yellow streak with adamantine luster, and transparent to translucent appearance.
The average density of stibiotantalite ranges from 6 to 7.4, and its hardness is 5.5.
Global Distribution
Stibiotantalite is distributed in the following places:
- Greenbushes tin placers, Wodgina district, Western Australia
- Muiˆane and other mines, Alto Ligonha, Mozambique
- Benson mine, Mtoko, Zimbabwe
- Topsham, Sagadahoc Co. Maine, USA
- San Diego Co. California
- Himalaya mine, Mesa Grande district, California
- Katerina, Stewart, and Vandenburg mines, Pala district, California
- Little Three mine, Ramona district, California
- Brown Derby pegmatite, Gunnison Co. Colorado
- Varutrask pegmatite, 15km north-west of Skelleftea, Vasterbotten, Sweden
- Voronya massif, Kola Peninsula, Russia
- Stak Nala, Gilgit district, Pakistan
Occurrence of Stibiotantalite and Useful Mineral Association
Stibiotantalite occurs as an uncommon accessory mineral in complex granite pegmatites.
It is closely associated with minerals like columbite–tantalite, cassiterite, alkalic beryl, lithiophilite, stibiomicrolite, microlite, allemontite, antimony, and tantalite.
References