Dewindtita
Dewindtita is a mineral with formula H₂Pb₃(UO₂)₆O₄(PO₄)₄·12H₂O), in the Fosfatos group. This specimen comes from Mina Pinhal do Souto, Tragos, Viseu, Portugal and joined the Terrium collection in 1985.
Description
Intense yellow dewindtite forming crusts and micro-aggregates on siliceous matrix. Bright green fluorescence under UV. Rare for the locality for both size and colour intensity. High radioactivity reading: 15 µSv/h.
History of this specimen
Collected c.40 years ago by Manuel Adonis, a Portuguese dealer who distributed the original pieces at fairs and into collections. Many of these Portuguese crustal uraniferous pieces circulated for years as "autunite" or "uranium phosphate", in good faith, on visual identification alone. Subsequent analyses by Rosell Minerales confirmed dewindtite as the main phase, with systematic associations of saleeite and plumbogummite, as well as other possible uraniferous phases yet to be determined.
About Dewindtita
A very rare secondary lead uranyl phosphate that forms in the oxidised zone of uranium deposits. It typically occurs as crusts, laminae or small aggregates of intense yellow colour and shows bright green fluorescence under ultraviolet light.
About the locality
A mine known for its limited output of rare uraniferous phosphates. Specimens with intense fluorescence, like this one, are uncommon and sought by specialised collectors.
Technical data
- Catalogue No.
- 0123
- Composition
- H₂Pb₃(UO₂)₆O₄(PO₄)₄·12H₂O)
- Name
- Dewindtita
- Group
- Fosfatos
- Category
- Núcleus Ardens
- Matrix
- Cuarzo, limonita
- Associations
- autunita, saleéita, plumbogummita, microasociaciones no identificadas
- Mine
- Mina Pinhal do Souto
- District / Municipality
- Tragos
- Province
- Viseu
- Country
- Portugal
- Size (cm)
- 4.8 x 3.7 x 2.9
- Weight
- 51.4 g
- Acquired
- 1985
- Etymology
- Named in honour of the Dutch mineralogist Johannes Dewindt, in recognition of his contributions to the study of uranyl phosphates.
- Quality
- Buena
- Value trend
- Al alza