Eroded material of the dump with increased content of arsenic sliding directly to Bodn rec stream below the dump is direct source of contamination. Higher content of Mg in siderite shifts the maximum of this reaction towards higher temperature. Ni content in all three phases which is anomalous in this region. Imported ores smelted in Kovohuty Krompachy plant were very probably the source of nickel in the studied slag. Composition of sulphide concentrate dump in Rudnany Tetrahedrite and chalcopyrite are the most abundant minerals of the studied dump in Rudnany deposit.
Angular grains show often cataclasis and fissures.
Replacement of chalcopyrite by tetrahedrite can be seen in some grains. Tetrahedrite is often replaced by secondary minerals along fissures, cavities and borders. Pyrite is less frequent as two previous minerals. Grains of pyrite are often enclosed or replaced by chalcopyrite. Gangue minerals siderite and quartz can be also observed.