Jun 11 2014
Calkinsite-(Ce) was named after Frank Cathcart Calkins (1878–1974), a geologist associated with the U.S. Geological Survey.
Properties of Calkinsite-(Ce)
The following are the key properties of calkinsite-(Ce):
- Cell Data
- Space group: P21221
- a = 9.57(2)
- b = 12.65(8)
- c = 8.94(2)
- Z = 4
- Crystal Data
- Orthorhombic
- Point group: 222
- As platy {010} crystals, to 1mm
- Twinning: Commonly twinned on {101}, compound and elongated along [100]
- X-ray powder pattern: 6.54 (10b), 3.27 (5), 4.78 (4), 4.49 (4), 2.931 (3b), 2.128 (3), 2.115 (3)
- Chemical Composition
| Elements |
Content |
| Ce2O3 |
32.05 |
| CO2 |
23.93 |
| La2O3 |
19.82 |
| H2O |
13.34 |
| Nd2O3 |
7.97 |
| Pr2O3 |
2.89 |
| Total |
[100.00] |
- Optical Properties
- Optical class: Biaxial (-)
- Pleochroism: X = yellow; Y = Z = colorless
- Orientation: X = b; Y = c; Z = a
- Dispersion: r < v , weak
- α = 1.569; β = 1.657; γ = 1.686
- 2V(meas.) = 54°
- Estimated Properties
| Electron density |
Bulk density (electron density) = 3.03 g/cm3
note: Specific gravity of calkinsite-(Ce) = 3.28 g/cm3 |
| Photoelectric |
PECalkinsite-(Ce) = 258.58 barns/electron
U = PECalkinsite-(Ce) x ρ electron density = 783.20 barns/cm3 |
| Fermion index |
Fermion index = 0.0010530403
Boson index = 0.9989469597 |
Radioactivity
|
Calkinsite-(Ce) is radioactive
|
How to Identify Calkinsite-(Ce)
Calkinsite-(Ce) can be identified in the field by its light yellow color. The mineral has {010} perfect and {101} distinct cleavage.
The density of calkinsite-(Ce) is 3.27 to 3.29 g/cm3, with a hardness of 2.5 – approximate to finger nail.
Global Distribution
Calkinsite-(Ce) is distributed in the following places:
- USA - From vermiculite prospects at the head of Big Sandy Creek, Rocky Boy’s Indian Reservation, about 40km east of Box Elder, Hill Co. Montana
- Russia - At the Vuoriyarvi carbonatite massif, Kola Peninsula
- Afghanistan - From the Khanneshin carbonatite complex
Occurrence of Calkinsite-(Ce) and Useful Mineral Association
Calkinsite-(Ce) occurs in a weathering product, closely associated with burbankite, in calcite veins cutting shonkinite in a composite stock.
It is often associated with minerals such as burbankite, ancylite, lanthanite, barite, goethite, calcite, biotite, chlorite, strontianite, dolomite, khanneshite, carbocernaite, mckelveyite, and pyrite.
References