Anhydrite
Query URLs
https://term.museum-digital.de/md-de/tag/8002
- Note
- Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium (baryte) and strontium (celestine) sulfates, as might be expected from the chemical formulas. Distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses. The Mohs hardness is 3.5, and the specific gravity is 2.9. The color is white, sometimes greyish, bluish, or purple. On the best developed of the three cleavages, the lustre is pearly; on other surfaces it is glassy. When exposed to water, anhydrite readily transforms to the more commonly occurring gypsum, (CaSO4·2H2O) by the absorption of water. This transformation is reversible, with gypsum or calcium sulfate hemihydrate forming anhydrite by heating to around 200 °C (400 °F) under normal atmospheric conditions. Anhydrite is commonly associated with calcite, halite, and sulfides such as galena, chalcopyrite, molybdenite, and pyrite in vein deposits.
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Anhydritlösung durch Regenwasser
Auf Anhydritblöcken, die...
Object information
Image: Ortsgeschichtliche Sammlung Walkenried - CC BY-SA -
Modell einer Gips-Quellungshöhle
Bei diesem Exponat handelt es...
Object information
Image: Ortsgeschichtliche Sammlung Walkenried - CC BY-SA -
Andhydrit
Das Mineral Anhdydrit gehört...
Object information
Image: Sammlungen der Universität Mainz - CC BY-NC-SA -
Laborflasche "Anhydrit"
Die Laborflasche mit...
Object information
Image: Heimatmuseum Dohna - CC BY-NC-SA -
Sammelbox mit verschiedenen Salzkristallen
In der rechteckigen Sammelbox...
Object information
Image: Werra-Kalibergbau-Museum, Heringen/W. - CC BY-NC-SA
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