Torbernita
Torbernita is a mineral with formula Cu(UO₂)₂(PO₄)₂·12H₂O, in the Fosfatos group. This specimen comes from Calo, Vimianzo, A Coruña, Galicia, España.
Description
Excellent crystallization of grass-green torbernite on a quartz matrix. They show bipyramidal forms truncated by pinacoidal faces. Or, in other words, tetragonal or hexagonal crystals shaped like a double pyramid, one on top of the other, whose tips are replaced by flat faces. I call them little barrels, and they are wonderful under the loupe.
History of this specimen
My first torbernite and the first specimen I bought from Fran (FDMinerals) from Seville.
About Torbernita
Torbernite is a hydrated copper uranyl phosphate belonging to the autunite group. It typically forms as a secondary mineral in the oxidation zones of uranium deposits, where water mobilizes uranium from primary minerals and deposits it together with copper and phosphate in fractures and cavities.
About the locality
Calo is one of those localities that exist in collections, but barely exist on the map. In May 2003, while searching for new kaolin mining sites in the Vimianzo area, geologist Manuel Montes Martínez found a three-meter cavity covered in torbernite crystals out in the hills. The company he worked for required around 70,000 metric tons of kaolin per year, and Montes was prospecting new kaolinized areas when he identified the site. He has never publicly revealed its exact location. The crystals are generally small, but their quality is exceptional, with some ranking among the finest European specimens of the species. Pieces are scarce and highly prized.
Technical data
- Catalogue No.
- 0146
- Composition
- Cu(UO₂)₂(PO₄)₂·12H₂O
- Name
- Torbernita
- Group
- Fosfatos
- Category
- Núcleus Ardens
- Matrix
- Cuarzo
- Mine
- Calo
- District / Municipality
- Vimianzo
- Province
- A Coruña
- Region
- Galicia
- Country
- España
- Size (cm)
- 7.5 x 5.2 x 2.8
- Weight
- 123 g
- Etymology
- From the Swedish chemist Torbern Olof Bergman, in recognition of his contributions to analytical chemistry.
- Quality
- Muy buena
- Value trend
- Al alza
Related specimens
- Aragonito (Blanco (Bulboso)) — España
- Barita — España
- Calcita (Dorada) — España
- Jacinto de Compostela — España
- Magnetita — España
- Magnetita — España
- Malaquita (Microbotrioidal) — España
- Piromorfita — China