Davidite
| Davidite-(La) | |
|---|---|
|
Davidite-(La) from Kazakhstan | |
| General | |
| Category | Oxide minerals |
| Formula (repeating unit) | (La,Ce,Ca)(Y,U)(Ti,Fe3+)20O38 |
| Strunz classification | 4.CC.40 |
| Crystal system | Trigonal |
| Crystal class |
Rhombohedral (3) H-M symbol: (3) |
| Space group | R3 |
| Unit cell | a = 10.376, c = 20.91 [Å]; Z = 3 |
| Identification | |
| Color | Black |
| Fracture | Subconchoidal to uneven |
| Tenacity | Brittle |
| Mohs scale hardness | ~6 |
| Luster | Vitreous |
| Diaphaneity | Opaque, translucent in very thin fragments |
| Specific gravity | 4.33 to 4.48 |
| Alters to | Metamict |
| References | [1][2][3][4] |
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Davidite is a rare earth oxide mineral with chemical end members La and Ce. It exists in two forms:
- Davidite-(La) (La,Ce,Ca)(Y,U)(Ti,Fe3+)20O38 discovered at Radium Hill mine, South Australia in 1906 and named by Douglas Mawson for Australian geologist Tannatt William Edgeworth David (1858-1934).[5]
- Davidite-(Ce) (Ce,La)(Y,U)(Ti,Fe3+)20O38 first described in 1960 from Vemork, Iveland, Norway.
References
- ↑ Davidite-La in Handbook of Mineralogy
- ↑ Davidite-La on Mindat
- ↑ Davidite-(La) on Webmineral
- ↑ Davidite-(Ce) on Webmineral
- ↑ Branagan, D.F. (2005): T.W. Edgeworth David: A Life: Geologist, Adventurer and "Knight in the Old Brown Hat", National Library of Australia, Canberra, p. 471. ISBN 0 642 10791 2
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