Allanita
Allanita is a mineral with formula (Ca,Ce,La,Y)₂(Al,Fe³⁺)₃(SiO₄)₃(OH), in the Supergrupo de la Epidota group. This specimen comes from Trimouns Talc Mine, Luzenac, Occitanie, Francia.
Description
Typical of this locality. The specimen is dominated by a long, dark, well-formed allanite crystal, clearly projecting over a base carpeted with white crystals. The main prism, typical of the monoclinic system, is elongated and slightly flattened, with smooth faces and well-defined edges. The cavity is open and shows the complete structure without obstruction, with a strong contrast between the dark crystal and the light matrix.
About Allanita
A classic of this French locality. Seldom found in well-defined crystals. It is a rare-earth element-bearing silicate, occurring as very elongate prismatic crystals, translucent and brown to toasted-honey in colour.
About the locality
In Luzenac (Ariège) allanite has been documented in pegmatitic and metamorphic veins. A classic locality for aesthetic crystals.
Technical data
- Catalogue No.
- 0071
- Composition
- (Ca,Ce,La,Y)₂(Al,Fe³⁺)₃(SiO₄)₃(OH)
- Name
- Allanita
- 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)) — Pakistán
- Autunita — Francia
- Calcopirita (Irisada) — Francia
- Parsonsita — Francia