Aug 15 2013
Overite was discovered in 1938 from the Little Green Monster mine, Clay Canyon, Utah Co., Utah, USA. It was named after Edwin J. Over, mineral collector, Colorado Springs, Colorado, USA, who first found the mineral.
Properties of Overite
The following are the key properties of Overite:
- Cell Data
- Space Group: Pbca
- a = 14.723(14)
- b = 18.746(16)
- c = 7.107(4)
- Z = 8.
- Crystal Data
- Orthorhombic.
- Point Group: 2/m 2/m 2/m.
- Crystals are platy to lath-like, flattened on {010} and elongated along [001], to 4 mm; forms include {010}, {100}, {110}, {121}, {021}. Commonly in subparallel aggregates, massive.
- X-ray Powder Pattern: 2.832 (100), 9.4 (80), 5.29 (60), 2.889 (60), 3.70 (50), 1.975 (50), 3.42 (40).
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| P2O5 |
38.9 |
38.32 |
| H2O |
22.04 |
21.89 |
| CaO |
16.1 |
15.14 |
| Al2O3 |
13.7 |
13.77 |
| MgO |
11.2 |
10.88 |
| Total |
101.9 |
100 |
- Optical Properties
- Optical Class: Biaxial (–)
- Orientation: X = c; Y = a; Z = b
- Dispersion: r > v, weak.
- α = 1.568(2)
- β = 1.574(2)
- γ = 1.580(2)
- 2V(meas.) = 75(10)°.
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.57 g/cm3
note: Specific gravity of Overite = 2.53 g/cm3 |
| Photoelectric |
PEOverite = 2.57 barns/electron
U = PEOverite x ρElectron density = 6.46 barns/cm3 |
| Fermion index |
Fermion index = 0.006
Boson index = 0.993 |
| Radioactivity |
Overite is not radioactive. |
How to Identify Overite
Overite is either colorless or occurs in light green variation. It has a transparent to translucent appearance, vitreous luster and has a white streak. Its fractures are brittle as that of glasses and non-metallic minerals. The hardness of overite ranges from 3.5 to 4, and its density is 2.53 g/cm3.
Global Distribution
Overite is distributed in the following places:
- Little Green Monster mine, Clay Canyon, about 9 km west of Fairfield, Utah Co., Utah, USA.
- Tanco pegmatite, Bernic Lake, Manitoba, Canada.
Occurrence of Overite and Useful Mineral Association
Overite occurs in a complex granite pegmatite and phosphate nodules. It is closely associated with apatite and variscite.
References