Jeremias Glück Mine (Fairy Grotto; Feengrotte), Garnsdorf, Saalfeld, Thuringia, Germany

In the late 19th and early 20th centuries, the mine was worked for silurian alum shales used as a raw material for the production of sulphuric acid. Around 1915, in order to preserve the coloured sulphate sinters formed by decomposition of pyrite and marcasite, the underground workings were transformed into a visitor's grotto.
Located at Garnsdorf, 2 km SW of Saalfeld.

References:
- Palache, C., Berman, H., & Frondel, C. (1951): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 1012.
- Rüger, F., Witzke, T., Grunewald, W., Langhammer, D., Senf, L. (1994): Die Saalfelder Feengrotten - eine mineralogische Kostbarkeit Deutschlands. Saalfelder Feengrotten, Geschichte, Geologie, Mineralien. Saalfeld, Germany, 25-51.
- Rüger, F., Senf, L. & Witzke, T. (1995): "Die Saalfelder Feengrotten: Seltene Sekundärmineralien aus Thüringen". Lapis 20(1), 15-26.

- http://www.feengrotten.de/