Minerals are naturally occurring cristals and therewith chemically and structurally homogenic parts of stones. Minerals can be divided into ten groups, like for example in elements (groups I), halogenids (group III) or in phosphate (group VIII).

The Grube Clara in Oberwolfach, source of the stones on the stockpiles, is characterized through its very high variety on minerals, which comprehend at the moment 375 different types of minerals. A list of all minerals found in the Grube Clara can be found here. Furthermore, the Mineralienatlas gives further information about the most important features of all types of minerals. If you are interested in the beauty of minerals under the microscope, we recommend the following website with a vast variety of Mineralienfotos.


6 examples for minerals of the Grube Clara:


schwerspatBarite, or also heavy spar, is the most frequently occurring mineral in the Grube Clara and is characterized by its high density. Often barite builds transparent cristals, which can also be coloured in other colours when other minerals has influenced the stone.


Malachit-SchallerMalachite is a mineral of the carbonate class with the chemical substance (Cu[(OH)2(CO3]. Malachite is created in the oxidation zone of copper fields and is therewith a secondary mineral. Its principal characteristic is its deep or bright green colour. 


Grube Clara Eigenfunde Erna u. Willi 140Fluorite, or in German also Flussspat, is the Calcium salt of hydrofluoric acid and is known under the chemical formula CaF2. Pure fluorite is transparent, but can also have some colours due to introduction of othe minerals. In UV-light, fluorite shows a strong fluorescence.


Silber-gediegenSilver is a chemical element and an easily malleable heavy metal with very high electrical and chemical conductivity. At the American continent, or to be more concrete, in Mexico, the USA, Canada, Bolivia and Peru can be found the most important silver deposits. 



Quartz is the second most abundant mineral in the Earth’s crust, is chemically described as SiO2 and has a pronounced cristal structure in diverse forms and colours. Quartz is also characterized through its hardness and its missing fissility.


Skorodit02Skorodite is a secondary mineral in the mineral class of phosphats, arsenates and vanadates and is a quite rare mineral. Skorodite is a typical part of oxidation zones of ore deposits with arsenic and iron content and can therefore be found in many locations across Germany (Black Forest, Sachsen, Fichtelgebirge…).