metalliferous minerals
Both the main metal-bearing minerals, blende and galena, are simple sulphides. Galena has all the typical features of sulphides: high density (7.6), moderate hardness (about 3) and, on recently broken surfaces, an unmistakable bright silvery gleam which, however, once in contact with the air, rapidly turns opaque and dark. Blende is generally coarse, and only rarely are fine crystals found.
The Schneeberg blende has high content of iron - which, together with the high content of cadmium (up to 4.5%) - is typical of these conditions of formation at high temperature. The iron gives the blende a dark, almost black, gleam, often reddish on fresh surfaces, which are generally modest in size. Blende exposed to air is often oxidized into many colours, which shine like the ring-dove's collar, as the miners called it, and is therefore quite unmistakable. Geologists define the Schneeberg deposit as a typical polymetallic enrichment of Pb-Zn. That is, as well as the prevailing minerals, blende (zinc sulphide, ZnS) and galena (lead sulphide, PbS), which were the main minerals mined, there are also quantities of other metalliferous minerals such as magnetopyrite, calcopyrite, pyrite, arsenopyrite, cobaltine, tetrahedrite, bournonite, meneghinite, magnetite, ganite, antimonite, and even pure silver, to name but a few. Then there are plentiful associated gangue minerals, such as siderite, ankerite, tremolite, anthophyllite, biotite, garnet, chlorite, quartz, calcite, etc.. As well as these primary minerals and those of the so-called vein facies, there are also several secondary minerals, originating from the transformation and chemico-physical decay of the primary ones, such as hydrozincite, greenockite, malachite, azzurrite, sepiolite, schneebergite, etc.. In total, more than one hundred minerals have been found and catalogued at Schneeberg, and there are still others ...
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