Tyuyamunita
Tyuyamunita is a mineral with formula Ca(UO₂)₂(VO₄)₂·5-8H₂O, in the Vanadatos group. This specimen comes from Rivas, Rivas Vaciamadrid, Madrid, España and joined the Terrium collection in 2025.
Description
Crust of microcrystalline, fluorescent yellow tyuyamunite on sepiolite matrix with pyrolusite. In effect, it appears as stains, some yellow and others black.
About Tyuyamunita
A calcium uranyl vanadate, i.e. a member of the autunite group in which vanadium replaces phosphorus. It is a neoformation mineral: it forms in the oxidation zone and can develop even in relatively recent historic mines. Minerals of this group have been documented on spoil heaps or in galleries in under a century, sometimes in just a few decades; they seldom take more than a few thousand years.
About the locality
The Sierra de Madrid is noted for this recent, limited find, with occasional specimens of high interest to collectors; Spanish pieces of this quality are very uncommon.
Technical data
- Catalogue No.
- 0121
- Composition
- Ca(UO₂)₂(VO₄)₂·5-8H₂O
- Name
- Tyuyamunita
- Group
- Vanadatos
- Category
- Núcleus Ardens
- Matrix
- Sepiolita
- Associations
- pirolusita
- Mine
- Rivas
- District / Municipality
- Rivas Vaciamadrid
- Province
- Madrid
- Country
- España
- Size (cm)
- 4.7 x 3.2 x 3
- Weight
- 25.5 g
- Acquired
- 2025
- Etymology
- From the Tyuya-Muyun district, Kyrgyzstan, where it was first described in 1912.
- Quality
- Buena
- Value trend
- Estable
Related specimens
- Abellaíta — España
- Abernathyita — España
- Abernathyita — España
- Abernathyita — España
- Aerenita — España
- Aerinita (fibrosa) — España
- Analcima — España
- Analcima — España