Allanita-(Ce)
Allanita-(Ce) is a mineral with formula Ca(REE³⁺)Al₂Fe²⁺(Si₂O₇)(SiO₄)O(OH), in the Supergrupo de la Epidota group. This specimen comes from Trimouns Talc Mine, Luzenac, Occitanie, Francia.
Description
A long, dark, well-formed allanite prism sheltered within a cavity and standing out against a matrix carpeted with white dolomite crystals.
About Allanita-(Ce)
It is a rare-earth silicate mineral seldom found as distinct crystals, and an absolute classic from this French locality, which produces specimens considered among the finest in the world. In its formula, "REE" (Rare Earth Elements) stands for a rare-earth element—such as Ce, La, Nd, or Y—whose specific dominance has not been identified.
About the locality
Trimouns Quarry, located at an altitude of around 1,700–1,800 metres in the French Pyrenees, is one of the largest talc operations in the world. Industrial production began in 1905. Although quarrying is restricted to the period from April to November, annual production has reached some 400,000 tonnes. In recent decades, Trimouns has also become a renowned mineralogical locality for its outstanding crystals of rare-earth-bearing minerals found in dolomite cavities, including our allanite, as well as parisite and bastnäsite, and much rarer species such as hingganite, iimoriite and dissakisite.
Technical data
- Catalogue No.
- 0071
- Composition
- Ca(REE³⁺)Al₂Fe²⁺(Si₂O₇)(SiO₄)O(OH)
- Name
- Allanita-(Ce)
- Group
- Supergrupo de la Epidota
- Category
- Cavella
- Matrix
- Calcita
- Associations
- dolomita
- Mine
- Trimouns Talc Mine
- District / Municipality
- Luzenac
- Province
- Occitanie
- Country
- Francia
- Size (cm)
- 8 x 6 x 5
- Weight
- 248.5 g
- Ex-collection
- Aleydis Soliveres
- Etymology
- Named in honour of Thomas Allan (1777–1833), a Scottish mineralogist who first described it.
- Quality
- Muy buena
- Value trend
- Estable
Related specimens
- Allanita-(Ce) ((Ce)) — Pakistán
- Autunita — Francia
- Calcopirita (Irisada) — Francia
- Parsonsita — Francia