Quartz from selected localities.
Germany | |
| Weisenberger, T.B., Spürgin, S., Lahaye, Y. (2014): Hydrothermal alteration and zeolitization of the Fohberg phonolite, Kaiserstuhl Volcanic Complex, Germany, International Journal of Earth Sciences, Vol. 103 (8). 2273-2300 |
| in the collection of Christof Schäfer |