Metaorbernita
Metaorbernita is a mineral with formula Cu(UO₂)₂(PO₄)₂·12H₂O, in the Fosfatos group. This specimen comes from Joachimsthal, Jáchymov, Karlovy Vary, Bohemia, República Checa and joined the Terrium collection in 1850.
Description
Tabular green crystals in a narrow band of the matrix. Edges slightly cracked from dehydration. Dull green colour typical of old metatorbernite. Reddish-brown matrix.
History of this specimen
In my files this specimen circulated in the earliest mineral cabinets and retains an exceptional double documentary lineage. The first label belongs to the pre-radioactivity era, prior to the discovery of radium, as shown by the designations "Uran-Glimmer" and "Kupferhfclliger Chalkolith"—literally 'uranium mica' and 'cupriferous chalcolite'—used between 1840 and 1880. The second places it at the beginning of the 20th century in the collection of Hans Jaklin (1874–1953), Senior Councillor and Imperial Mining Academician, when Jachymov supplied uraninite to the glass industry and, shortly afterwards, to the nascent radiological sector. There it was reclassified as "Kupferuranit", already within modern chemical nomenclature. In my collection its ID is U-238.
About Metaorbernita
A hydrated copper uranyl phosphate, but less hydrated here: as a 19th-century piece it has partially dehydrated to metatorbernite, hence the dull green colour.
About the locality
Today Jachymov is recognised mainly as a spa town, specifically a radon spa. The history goes much further. During the 16th–18th centuries, Joachimsthal was a very rich mining district for its silver veins, in whose lower levels appeared black, heavy minerals with a strange smell when crushed: they were pitchblende—the 'black deceit' to miners—and some of its alteration products, such as this torbernite. In fact, no one knew what they were; apart from getting in the way, they had only one useful property that was recognised in Bohemia fairly early: mixed with silica and melted they produced a very intense green glass. Between the end of the 19th and the start of the 20th century, everything began to change. In 1896 Henri Becquerel discovered radioactivity while investigating uranium salts. Marie and Pierre Curie, seeking the cause of that mysterious energy, analysed tonnes of pitchblende from Je1chymov that they crushed in their humble laboratory. In 1898 they discovered polonium and radium, from which they obtained the first decigrams. After these discoveries, uranium mineralogy was reorganised. Between 1900 and 1930 more precise chemical names were introduced such as "Kalkuranit" (autunite), "Kupferuranit" (torbernite) and "Uranpecherz" (uraninite). From then on, Joachimsthal passed from a classic mining district to the cradle of modern radioactivity. After 1945 the former Sankt Joachimsthal fell under Soviet control and was renamed Jachymov, the name it retains today.
Technical data
- Catalogue No.
- 0238
- Composition
- Cu(UO₂)₂(PO₄)₂·12H₂O
- Name
- Metaorbernita
- Group
- Fosfatos
- Category
- Núcleus Ardens
- Mine
- Joachimsthal
- District / Municipality
- Jáchymov
- Province
- Karlovy Vary
- Region
- Bohemia
- Country
- República Checa
- Size (cm)
- 5 x 4.5 x 2.5
- Weight
- 41.7 g
- Acquired
- 1850
- Ex-collection
- Gabinete austrohúngaro (s. XIX) → Hans Jaklin
- Etymology
- Named after Torbern Bergman.
- Quality
- Top
- Value trend
- Al alza
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