Geology and mineralogy

The Zlatý Kopec mass is made up of two skarn horizons imbeded in foliated rock with deposits of quartzite, amphibolite and skarn rocks. The original makeup of the now metamorphic rock - phyllite ‐ was layers of sandy‐clay sediment alternating with volcanic rocks and tuff.

The original substrata of skarn were calcium layers; these minerals transformed into phyllite rock during the Variscan (hercynian) orogeny process. Phyllite in the Zlatý Kopec area is part of the tellehäuser layers, a stratification section of the so‐called frauenbašské series from the Ordovician Period, which makes up the area of Krušné Hory and Smrčin west of the Nejdek‐ Eibenstock granite pluton.

The intrusion of the granite massif happened during the later stages of the Variscan orogeny; granite massif was the primary mineral of the ore creating elements. The actual mineral deposits are made up of a number of ore‐rich horizons with sections of skarn. Only two of them ‐ the main skarn area and the Hugo area ‐ reach the actual surface. The main horizon is 800m in length and 300m wide, the average width varies between 1.5 – 3m and up to 9.5m, and forms a slightly undulating plateau at a general slope of 5 ‐ 20° k NE.

This area where there are deposits of ore was the subject of past mining activity (Johannes & Kohlreuter mines). The main ore minerals are iron oxide, chalcopyrite, zinc sulphide, arsenic trioxide, pyrite, and pyrrhotite. The mineral deposits are intertwined with a number of tectonic structures and quartz‐fluorite veins.

The Zlatý Kopec mineral deposit is known for its diverse mineral composition. Apart from the main ore minerals which are iron (Fe3O4), chalcopyrite (CuFeS2), zinc sulfide (ZnS), tin (SnO2), arsenopyrite (FeAsS), pyrite (FeS2) and pyrrhotite (FeS), we can also find iron arsenide (FeAs2), helvite (Mn4[S(BeSiO4)3]), malayaite (CaSn[O|(SiO4)], and greenockite (CdS).

A number of precious minerals have been identified in Zlatý Kopec which have been found in only a few other sites around the world, these being schoenfliesite, wickmanite, and natanite.

Minerals containing tin from Zlatý Kopec