Moreauita
Moreauita is a mineral with formula Al₃(UO₂)(PO₄)₃(OH)₂·13H₂O, in the Fosfatos group. This specimen comes from Valdeíñigo, Tejeda de Tiétar, Cáceres, Extremadura, España and joined the Terrium collection in 2013.
Description
Small canary-yellow moreauite crystals arranged as spherules, micaceous "open book" aggregates and earthy crusts on ferruginous matrix. A very representative specimen from La Gagüera, with several growth forms clearly visible. Shows low radioactivity: 0.20 µSv/h at close range.
History of this specimen
It came from a boulder that had been kept for more than ten years until its owner decided to break it and prepare it for sale. That lot produced some large pieces, including this specimen, which passed from Francisco Becerra to my collection.
About Moreauita
Scientific rarity. Described as a species in 1985, moreauite is a rare hydrated aluminium uranyl phosphate formed by secondary processes. It is very scarce, little studied, and extremely rare in collections.
About the locality
La Gagüera. Spanish reference locality for the species. La Gagüera mine, at Valdeíñigo (Cáceres), is the first record of moreauite in the Iberian Peninsula and among the earliest confirmed outside the type locality. Its specimens are among the best in the world. It was a uranium mine working a granitic pegmatite, now inaccessible, restored under a layer of several metres of backfill, which makes obtaining new specimens impossible... although an occasional micro still seems to be found on the dumps.
Technical data
- Catalogue No.
- 0181
- Composition
- Al₃(UO₂)(PO₄)₃(OH)₂·13H₂O
- Name
- Moreauita
- Group
- Fosfatos
- Category
- Núcleus Ardens
- Matrix
- Matriz ferruginosa
- Mine
- Valdeíñigo
- District / Municipality
- Tejeda de Tiétar
- Province
- Cáceres
- Region
- Extremadura
- Country
- España
- Size (cm)
- 3 x 2 x 2
- Weight
- 18 g
- Acquired
- 2013
- Ex-collection
- Francisco Becerra
- Etymology
- Named in honour of Jacques Moreau (1922–2010), a French mineralogist specialised in uranium compounds.
- Quality
- Muy buena
- Value trend
- Al alza
Related specimens
- Abellaíta — España
- Abernathyita — España
- Abernathyita — España
- Abernathyita — España
- Aerenita — España
- Aerinita (fibrosa) — España
- Analcima — España
- Analcima — España