Plaster cave
As gypsum cave one will cave in gypsum rock called. When it comes into contact with seepage water, anhydrite absorbs water and turns into gypsum. Anhydrite is a sediment - mineral and is often formed as an evaporation product from sea water , it is almost always coarse-grained or massive, rarely crystalline . The longest gypsum cave is the Optymistytschna cave in Ukraine.
Gypsum caves in Germany
- The Heimkehle at Uftrungen in the Harz
- The Mathildenhöhle in Hils (Leinebergland) near Hanover in Lower Saxony is the only cave in Europe in the Jura gypsum ,
- The crystal grotto in the Marienglashöhle near Friedrichroda with impressive formations made of selenite
- The Barbarossa Cave at Kyffhäuser near Nordhausen ,
- The Segeberger Kalkberg Caves are the longest gypsum caves in Germany that the public can enter
- The Wimmelburger Schlotte near Eisleben (Saxony-Anhalt) is the longest known gypsum cave in Germany - but not open to the public
- The gypsum cave Höllern , the largest in southern Germany, in Bavaria in the nature reserve "gypsum cave Höllern and gypsum hill seven humps"
Gypsum caves in Austria
The Trübbach Cave in Vorarlberg
Gypsum caves in Switzerland
The Grotte de la Crête de Vaas near Sierre , ( Canton of Valais ) is the largest gypsum cave in the Alpine region.