May 24 2014
Sasaite is an orthorhombic white mineral containing sulfur, phosphorus, oxygen, iron, hydrogen, and aluminum. The mineral was first found in 1978 from the West Dreifontein cave, near Carlstonville in Transvaal, South Africa.
It was named for the South African Speleological Association (SASA), whose members collected the first specimens.
Properties of Sasaite
The following are the key properties of Sasaite:
- Cell Data
- Space Group: n.d
- a = 10.75
- b = 15.02
- c = 46.03
- Z = 6
- Crystal Data
- Orthorhombic
- Point Group: n.d
- Crystals with rhombic outline, {110}, small {100}, {010}, to 20µm, stacked in twisted vermiform aggregates; in veinlets, nodules, and efflorescences
- X-ray Powder Pattern: 11.52 (100), 2.901 (42), 6.99 (23), 7.51 (22), 6.30 (21), 4.214 (18), 3.262 (18)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| H2O |
49.50 |
[32.98] |
| P2O5 |
24.16 |
32.79 |
| Al2O3 |
21.65 |
29.81 |
| SO3 |
2.77 |
3.72 |
| Fe2O3 |
1.05 |
0.13 |
| CaO |
0.12 |
0.08 |
| MgO |
0.07 |
- |
| F |
0.03 |
- |
| SrO |
0.02 |
- |
| MnO |
0.01 |
- |
| -O = F2 |
0.01 |
- |
| CuO |
- |
0.38 |
| K2O |
- |
0.11 |
| insol. |
0.07 |
- |
| Total |
99.44 |
[100.00] |
- Optical Properties
- Optical Class: Biaxial (–)
- Orientation: X˜ c; Y˜b; Z˜a
- α = 1.465(1)
- β = 1.473(1)
- γ = 1.477(1)
- 2V(meas.) = n.d
- Estimated Properties
| Electron density |
Bulk density (electron density) = 1.83 g/cm3
note: Specific gravity of Sasaite = 1.75 g/cm3 |
| Photoelectric |
PESasaite = 1.97 barns/electron
U= PESasaite x ρElectron density = 3.60 barns/cm3 |
| Fermion index |
Fermion index = 0.001
Boson index = 0.998 |
Radioactivity
|
Sasaite is not radioactive
|
How to Identify Sasaite
Sasaite is an earthy white mineral, having perfect cleavage and white streak. It can be formed as nodules, having irregular protuberances over the surface.
The density of sasaite is 1.75 g/cm3, and its hardness ranges from 2 to 3.
Global Distribution
Sasaite is distributed in the following places:
- West Driefontein Cave, Carlstonville, west Transvaal, South Africa
- Skipton lava tube caves, 40km southwest of Ballarat, and near Cheshunt, Victoria
- Rapid Creek, Yukon Territory, Canada
- Feengrotten (Cave), near Saalfeld, Thuringia, Germany,
Occurrence of Sasaite and Useful Mineral Association
Sasaite occurs in veinlets in slate, and it is rarely formed from acidic phosphate-sulfate-rich solutions derived from bat guano reacting with clay minerals in cave soil.
The minerals that are closely related to sasaite include apatite, leucophosphite, phosphosiderite, strengite, and variscite.
References