Schaubergwerk Morassina

Useful Information

Location:	Schmiedefeld. (50.534653, 11.224997)
Open:	NOV to MAR daily 11-15. APR to OCT Mon-Fri 9-17, Sat-Sun 10-17. [2022]
Fee:	Adults EUR 13, Children (3-15) EUR 9, Students EUR 10. [2022]
Classification:	Alum Mine Diadochite Speleotherapy
Light:	Incandescent Electric Light System
Dimension:	L=2,000 m, T=7 °C.
Guided tours:	D=60 min.
Photography:	forbidden, permit may be purchased.
Accessibility:	short tour available
Bibliography:
Address:	Schaubergwerk Morassina, Schwefelloch 1, 98739 Schmiedefeld, Tel: +49-36701-61577, Fax: +49-36701-20735. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

1683	first written mention.
1717	mine bought by the merchant Johann Leonard Morassi and renamed Morassina.
1750	sold to the merchant Frege from Leipzig.
1850	new, cheaper methods to produce alum and vitriol make the mining unprofitable.
1860	mine closed.
1951	prospection by miners of the SDAG Wismut in search of uranium ores.
01-OCT-1989	development as a show mine.
SEP-1992	development completed.
30-MAY-1993	opened to the public.
1997	speleotherapy in Sankt-Barbara Heilstollen opened to the public.

Geology

The black alum slate contains a high amount of iron sulfate (FeS₂) in form of tubers or granules. This mineral is also called pyrite or marcasite, depending on its habit. In contact with water it dissolves, producing sulfuric acid and iron oxide. The aggressive acid expedites the dissolution process.

Another by-product of this chemical process is alum which is used to produce vitriol by adding any kind of metal. Copper vitriol is the most useful of those metal sulfates, and was used for tanning, for the production of paper and many other purposes at pharmacies and laboratories. Another important by product of the dissoltuion of iron sulfate is water free iron oxide (Fe₂O₃), a very light-fast pigment, which was sold under the name Englischrot (English Red).

Description

The Schaubergwerk Morassina (show mine Morassina) resembles a dripstone cave. There are natural mineral deposits, which were formed after the end of the mining activities. Water seeping through the rock transported dissolved minerals into the tunnels and formed colourful dripstones by depositing material over a century. The dripstones are coloured by the containing minerals. Aluminium compounds case blue-green colours, phosphorus iron compounds cause yellow and fawn colours.

In the Alaunbergwerk Morassina (alum mine Morassina) slate was mined, which was used for the production of alum and vitriol. After the end of the mining in the mid 19th century the mine was closed until in 1951. Geologists of the SDAG Wismut were unsuccessfully looking for uranium deposits in this mine. But they discovered a different treasure, the abundant dripstones in the aborted tunnels. They formed in only one century, which is many times faster than dripstones in karst caves. The reason is the different chemistry, this are not calcite formations but diadochite. This often porous rock, often soft while wet, is the deposition of various mineral salts, which are much better soluble than limestone and thus transported much faster.

The guided tour starts with coats, which are handed out to protect the clothes of the visitors from the dripping water. The mine is entered through the opening of the Neuer Stollen (new tunnel). First the Stahlblaue Grotte (Steel Blue Grotto) is reached, which shows the first dripstones. The Fantasiegrotte (Fantasy Grotto) offers even more dripstone, most of them of a bright white colour which is in contrast to the black surrounding rocks. A wooden ladder slowly overgrown by dripstones gives a good impression of the growth rate. Through Kleine Grotte (Small Grotto) and the Kurzer Stollen (Short Tunnel) the trail leads to the Rokokosaal (Rococo Hall). Here are the most impressive and amd mighty dripstones plus numerous very long soda straws. A geologic window allows a glimpse of the tectonic structure of the surrounding rocks. The Alexander von Humboldt Verbruch (Alexander von Humboldt collapse) gives an impression of the situation of the mine in July 1792 when Alexander von Humboldt researched here in the Schwefelloch (sulfur hole). The Märchengrotte (Fairy Tale Grotto) is made for children, all speleothems were named with fantasy terms. The huge rimstone pools are impressive too.

In a part of the old mine, the Sankt Barbara Heilstollen (Saint Barbara speleotherapy tunnel), the curative forces of nature are used for speleotherapy. The Stahlblaue Grotte at the entrance is used for weddings and baptism.