May 28 2014
The name caoxite is an acronym with two possible meanings. One is for the key chemical components present in the mineral - Calcium and Oxalate. The other is for the Centennial Anniversary Of X-rays, an essential analytical tool in modern mineralogy.
Properties of Caoxite
The following are the key properties of caoxite:
- Cell Data
- Space group: P1
- a = 6.097(1)
- b = 7.145(1)
- c = 8.434(1)
- α = 76.54(1)°
- β = 70.30(1)°
- γ = 70.75(1) °
- Z = 2
- Crystal Data
- Triclinic
- Point group: 1
- As elongated crystals, tabular on {010}, with polygonal outline, to 0.5mm
- As crystalline spherulites
- X-ray powder pattern: 5.52 (vs), 2.834 (s), 7.92 (m), 5.26 (m), 4.99 (m), 3.643 (m), 2.758 (m)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| C2O3 |
[39.54] |
39.54 |
| CaO |
30.03 |
30.79 |
| H2O |
[29.67] |
29.67 |
| Total |
[99.24] |
100.00 |
- Optical Properties
- Optical Class: Biaxial (–)
- α = 1.483(3) (α’); β = [1.516]; γ = 1.533(3) (γ’)
- 2V(meas.) = 70(2) °
- Estimated Properties
| Electron density |
Bulk density (electron density) = 1.91 g/cm3
note: Specific gravity of caoxite = 1.85 g/cm3 |
| Photoelectric |
PEcaoxite = 2.85 barns/electron
U=PEcaoxite x ρ electron density = 5.45 barns/cm3 |
| Fermion index |
Fermion index = 0.0020479048
Boson index = 0.9979520952 |
Radioactivity
|
Caoxite is not radioactive
|
How to Identify Caoxite
Caoxite can be identified in the field by its colorless structure. Its transparent form has {010} good cleavage. This mineral has a vitreous luster with white streak.
The density of caoxite is 1.85 g/cm3 with a hardness of 2 to 2.5 – between gypsum and finger nail. The fracture on this mineral is brittle – uneven.
Global Distribution
Caoxite is distributed mainly in Italy, from the Cerchiara mine, near Faggiona, Val di Vara, in Liguria.
Occurrence of Caoxite and Useful Mineral Association
Caoxite typically occurs in veinlets cutting metamorphosed Mn–Ba-rich cherts in an obducted ophiolite.
It is often associated with minerals such as quartz, barite and manganese oxides.
References