Torbernite is a mineral with the chemical formula Cu(UO2)2(PO4)2·12H2O. It is a bright, radioactive green crystal that may be found in the oxidation zone of copper-uranium deposits. The term is properly spelled as [tɔːˈbəːnaɪt] in IPA phonetic transcription, with the emphasis on the second syllable. The word derives from the name of the Swedish chemist Jöns Jakob Berzelius, who named it after the Swedish geologist Johan Torberg. Torbernite has been used as an ore of uranium in the past, and its bright green crystals make it a popular collector's mineral today.
Torbernite is a mineral belonging to the uraninite group, which is known for its distinct green color. It is a secondary mineral, meaning it forms from the alteration of other primary uranium-bearing minerals. The name "torbernite" is derived from the Torberge region in Saxony, Germany, where it was first discovered.
Chemically, torbernite is a hydrated copper uranyl phosphate. Its chemical formula can be represented as Cu(UO2)2(PO4)2 • 12H2O. This mineral typically crystallizes in the orthorhombic crystal system, forming prismatic to acicular crystals that often appear in radiating or botryoidal aggregates. It has a Mohs hardness of 2.5-3, indicating its relatively low level of hardness.
Torbernite is renowned for its vibrant green color, which can range from lime green to emerald green. This coloration is attributed to the presence of uranium in its chemical composition. Its lustrous appearance and striking color make it a sought-after mineral among collectors and mineral enthusiasts.
Due to its uranium content, torbernite is also of interest in terms of its radioactivity. It contains low levels of radioactivity, which can be detected using a Geiger-Mueller counter. However, the risks associated with torbernite are generally low, as long as it is handled and stored properly.
In summary, torbernite is a vivid green secondary mineral belonging to the uraninite group. It is composed of copper, uranium, phosphate, and water. Its distinct color and striking crystal formations make it a prized specimen in the world of mineralogy.
The word "Torbernite" derives from the Swedish word "torbernit", which was coined by the Swedish chemist Jöns Jakob Berzelius in 1822. Berzelius named the mineral in honor of the Swedish chemist and industrialist Carl Johan Torbern Bergman.