Tin deposit Rolava on the northern slopes of Plochá hora (936 m) is the largest deposit of greisen type in the Nejdek granite Massif. Tin and tungsten ore were mined with a few breaks since the late Middle Ages until the 20th century. After 1938 a new treatment plant was designed. It was supposed to supply metal for the German arms industry. After 1940, two new shafts were mined. In May 1945 the national enterprise “Rudné a tuhové doly” took over. However after unsuccessful results of subsequent prospecting the whole area was deserted, and turned into a ghost place with reinforced concrete skeletons of buildings which are gradually devoured by vegetation.
The tin and tungsten mineralization were formed during so called pneumatolyse in final stages of granite body solidification at temperatures of 400–600 °C. During the pneumatolyse, volatile substances were loose and affect the granite body as well as surroundings rocks. Specific mineral enriched by B, Cl, F, Li, lanthanides etc., especially tourmaline, beryl and topaz were formed. Results of influence of fluorine rich vapours are the so called greisens, rock compound of quartz, mica and others mineral. High content of fluorine, lithium and some metals is typical for greisen minerals.
The mouth of the drainage gallery of St. George can be found about 2km east of the mining area. It was renewed during World War II. Concrete portal from 1941 is still well preserved and several depressions show its direction. Strong water discharge bears evidence of the prevailing function of the mine.
Fig.:
1. The Rolava mining plant in World War II
2. Ruins of the ore processing plant of the Zinnbergbau Sudetenland
3. Circular sedimentation tank
4. Ore containers