Ammonium illite from anchimetamorphic shales associated with anthracite in the Zemplinicum of the western Carpathians

Abstract

Abstract Ammonium-rich illite was identified in shales from the meta-anthracite coalfields of Zemplinicum (the Western Carpathians) together with K-illite and Na-illite using X-ray diffraction (XRD), infrared absorption and chemical analyses. The NH 4 -abundance in illite was quantified by the position of the 005 XRD reflection and by chemical analysis. Ammonium-bearing illite was probably formed in the temperature interval 200-270°C by illitization of a kaolinite precursor in the presence of ammonium.