Autunita
Autunita is a mineral with formula Ca(UO₂)₂(PO₄)₂·10-12H₂O, in the Fosfatos group. This specimen comes from Mina Les Oudots, Autun, Saona y Loira, Francia and joined the Terrium collection in 2025.
Description
Intensely green laminar crystals with strong lustre, sharply defined on granitic matrix. Very strong UV fluorescence. Protected by a lacquer.
History of this specimen
First radioactive piece in my collection, and founding mineral of Núcleus Ardens. It carries number 92 as a direct homage to the atomic weight of uranium, the heaviest natural element on Earth. It arrived in an almost theatrical scene: a box one metre by seventy, and in the centre, solitary and protected, a small Tupperware containing this jewel of laminar crystallisation. It comes from the type locality, Les Oudots, near Autun (France), which reinforces its historical and symbolic value.
About Autunita
A hydrated uranyl-calcium phosphate noted for its bright green colour, laminar habit and intense fluorescence. It forms as a secondary mineral by oxidation of uranium minerals in hydrothermal veins or pegmatites. It is radioactive and dehydrates over time in dry air, transforming into metautunite.
About the locality
From Les Oudots, near Autun, the type locality of the species, in the French department of Saône-et-Loire.
Technical data
- Catalogue No.
- 0092
- Composition
- Ca(UO₂)₂(PO₄)₂·10-12H₂O
- Name
- Autunita
- Group
- Fosfatos
- Category
- Núcleus Ardens
- Matrix
- Matriz granítica
- Mine
- Mina Les Oudots
- District / Municipality
- Autun
- Province
- Saona y Loira
- Country
- Francia
- Size (cm)
- 6 x 5 x 4
- Weight
- 134.9 g
- Acquired
- 2025
- Etymology
- Named by Brooke and Miller in 1854 in honour of Autun (France), the type locality where it was first described.
- Quality
- Muy buena
- Value trend
- Al alza