Parsonsita
Parsonsita is a mineral with formula Pb₂(UO₂)(PO₄)₂·2H₂O, in the Fosfatos group. This specimen comes from Lachaux, Puy-Guillaume, Puy-de-Dôme, Auvergne-Rhône-Alpes, Francia and joined the Terrium collection in 1957.
Description
Thin, dull yellowish crusts of parsonsite on light grey matrix, with small, more intense earthy patches along fracture zones. Microgranular texture with no notable lustre, typical of alteration uranium phosphates. Emits 16.5 µSv/h.
History of this specimen
I got it from Dr Karl Walenta, with four historical labels: one from the Mineralogisches Institut Bonn (1959) signed by Dr Walenta himself; another from the C.E.A. (Commissariat à l’Énergie Atomique); a later typed label reading "Parsonsite (Lachaux)"; and a fourth analytical sheet with chemical notes "U+, Pb+, P+, As-" dated 26.8.57. I keep the specimen in its original museum cardboard box with hinged lid and protective glass. I numbered it 0234 after its less common natural isotope.
About Parsonsita
Scientific rarity. Parsonsite is a hydrated lead-uranium phosphate, pale yellow to mustard in colour, formed as a secondary mineral in the oxidation zone of uranium deposits. It usually occurs as earthy crusts or microcrystalline aggregates.
About the locality
The Lachaux deposit, in the department of Puy-de-Dôme, is a classic French locality for uranium phosphates. Known for associations with torbernite, uranocircite, autunite and meta-autunite, related to hydrothermal alteration of granite.
Technical data
- Catalogue No.
- 0234
- Composition
- Pb₂(UO₂)(PO₄)₂·2H₂O
- Name
- Parsonsita
- Group
- Fosfatos
- Category
- Núcleus Ardens
- Matrix
- Matriz gris claro con costras amarillas
- Mine
- Lachaux
- District / Municipality
- Puy-Guillaume
- Province
- Puy-de-Dôme
- Region
- Auvergne-Rhône-Alpes
- Country
- Francia
- Size (cm)
- 6 x 4.5 x 3
- Weight
- 108.7 g
- Acquired
- 1957
- Ex-collection
- Dr. Karl Walenta (Mineralogisches Institut Bonn)
- Etymology
- Named in honour of the Australian mineralogist Charles Parsons, in recognition of his work on uranium minerals.
- Quality
- Top
- Value trend
- Al alza