Sep 5 2013
Romeite is a calcium antimonite mineral first discovered in 1841 from the San Marcel mine, Piedmont, near Vipiteno, Italy. It is a member of stibiconite group. The mineral was named after Jean Baptiste Louis Romé de L'Isle, eminent early French crystallographer.
Properties of Romeite
The following are the key properties of Romeite:
- Cell Data
- Space Group: Fd3m
- a = 10.24–10.31
- Z = 8.
- Crystal Data
- Cubic
- Point Group: 4/m 3 2/m
- As octahedra, to 1 mm, with subordinate {001}, {110}, {112}, {113}, {133}; in crystalline aggregates; massive
- Twinning: Uncommon on {111}
- X-ray Powder Pattern: 2.95 (10), 6.0 (8), 1.827 (8), 3.09 (7), 1.549 (7), 2.57 (6), 0.869 (6).
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| Sb2O5 |
74.72 |
72.17 |
74.26 |
| CaO |
15.81 |
19.01 |
25.74 |
| MnO |
6.27 |
0.43 |
- |
| F |
3.50 |
- |
- |
| H2O |
1.39 |
0.66 |
- |
| FeO |
1.12 |
2.92 |
- |
| Na2O |
0.81 |
2.03 |
- |
| PbO |
0.51 |
- |
- |
| MgO |
0.35 |
- |
- |
| TiO2 |
0.30 |
- |
- |
| K2O |
0.17 |
- |
- |
| -O= F2 |
- |
[1.47] |
- |
| Total |
100.12 |
[100.58] |
100.00 |
- Optical Properties
- Optical Class: Isotropic; may be anomalously biaxial, zoned or sectored.
- n = 1.817–1.854.
- Estimated Properties
| Electron density |
Bulk density (electron density) = 4.62 g/cm3
note: Specific gravity of Romeite = 5.05 g/cm3 |
| Photoelectric |
PERomeite = 148.95 barns/electron
U = PERomeite x ρElectron density= 688.27 barns/cm3 |
| Fermion index |
Fermion index = 0.009
Boson index = 0.99 |
|
Radioactivity
|
Romeite is not radioactive. |
How to Identify Romeite
Romeite occurs in different colors ranging from white to yellow and yellowish brown. It has imperfect cleavage, vitreous luster and brownish yellow streak. The average density of romeite is 5.05 g/cm3, and its hardness ranges from 5.5 to 6. This mineral can be formed as crust-like aggregates on matrix or a loose, poorly-coherent powdery mass. The mineral has transparent to sub-opaque and imperfect cleavage.
Global Distribution
Romeite is distributed in the following places:
- Praborna mine, south of St. Marcel, Val d’Aosta, Piedmont, Italy.
- Radstadter Tauern-Pass, Salzburg, Austria.
- Langban and Jakobsberg, Varmland, Sweden.
- Franklin, Sussex Co., New Jersey, USA.
- Green prospect, Mopung Hills, Lake district, Churchill Co., Nevada.
- Tripuhy cinnabar mine, Ouro Prˆeto, Minas Gerais, Brazil.
- Tai Lee mine, Siput Utara, Perak, Malaysia.
Occurrence of Romeite and Useful Mineral Association
Romeite occurs as a secondary mineral in some manganese-bearing hydrothermal mineral deposits having undergone metamorphism. The minerals that are related to romeite include andradite, diopside, willemite, sarkinite, yeatmanite, manganese oxides and epidote.
References