Clarkeite
Clarkeite is a uranium oxide mineral with the chemical formula(Na,Ca,Pb)2(UO2)2(O,OH)3 or (Na,Ca,Pb)(UO2)O(OH)·0-1H2O.
| Clarkeite | |
|---|---|
| General | |
| Category | Minerals |
| Formula | (Na,Ca,Pb) 2(UO 2) 2(O,OH) 3 or (Na,Ca,Pb)(UO 2)O(OH)•0-1H 2O |
| IMA symbol | Cke[1] |
| Strunz classification | 4.GC.05 |
| Dana classification | 5.4.1.1 |
| Crystal system | Trigonal |
| Space group | R3m (No. 166) |
| Unit cell | 239.11 Å3 (Calculated from unit cell) |
| Identification | |
| Colour | Dark red-brown, dark brown |
| Cleavage | None observed |
| Fracture | Conchoidal, sub-conchoidal |
| Mohs scale hardness | 4–4.5 |
| Luster | Resinous, waxy, greasy |
| Streak | Yellow-brown |
| Diaphaneity | Translucent |
| Specific gravity | 6.39 |
| Density | 6.39 g/cm3 (Measured) |
| Birefringence | 0.111 |
| Pleochroism | Weak |
| 2V angle | Measured 30° to 50°, Calculated 32° |
| Dispersion | Relatively weak |
| Other characteristics |  Radioactive |
Clarkeite is a uranium oxide mineral with the chemical formula(Na,Ca,Pb)
2(UO
2)
2(O,OH)
3 or (Na,Ca,Pb)(UO
2)O(OH)·0-1H
2O.
Its color varies from dark brown to reddish orange. Clarkeite forms by oxidation and replacement of uraninite late during pegmatite crystallization. Although uraninite-bearing granite pegmatites are common, clarkeite is rare and occurs intimately intergrown with other uranium minerals.
It is known from only two localities; the Spruce Pine pegmatite district in western North Carolina, US, and Rajputana, in the Ajmer district, India. Clarkeite is the only known naturally occurring high-temperature uranate. The general formula for ideal clarkeite is Na[(UO
2)O(OH)](H
2O)
0–1.
It was named for Frank Wigglesworth Clarke (1847–1931), American mineral chemist, and former chief chemist of the United States Geological Survey.
See also
References
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- Clarkeite: New chemical and structural data
- Clarkeite: Clarkeite mineral information and data
- WebMineral
Content Disclaimer
Informasi ini disarikan dari Wikipedia dan disajikan kembali untuk tujuan edukasi. Konten tersedia di bawah lisensi CC BY-SA 3.0. Kami tidak bertanggung jawab atas ketidakakuratan data yang bersumber dari kontribusi publik tersebut.
- The information displayed on this website is sourced in part or in whole from Wikipedia and has been adapted for the purpose of restating it. We strive to provide accurate and relevant information, however:
- There is no guarantee of absolute accuracy. Wikipedia is an open, collaborative project that can be edited by anyone, so information is subject to change.
- It is not intended to constitute professional advice. The content displayed is for informational and educational purposes only. For important decisions (e.g., medical, legal, or financial), please consult a professional.
- Content copyright. Wikipedia is licensed under the Creative Commons Attribution-ShareAlike License (CC BY-SA). This means that content may be reused with appropriate attribution and shared under a similar license.
- Responsible use. Any risk arising from the use of information from this website is entirely the responsibility of the user.