Szakáll Sándor - Jánosi Melinda: Minerals of Hungary (Topographia Mineralogica Hungariae 4. Miskolc, 1996)

Fig. 62 RHODOCHROSITE (8 cm sp) Úrkút In the limestones of the Cretaceous sedimentary rocks the chief mineral is calcite (Ajka, vicinity of Sümeg). This is also true in the high quality Cretaceous coal deposits near Ajka where it is accompanied by pyrite and marcasite. These deposits have been mined since the middle of the 19th century. Here, in the so-called "amberseams" were found the "ajkaite" nodules (up to fist-size). "Ajkaite" is a fossil resin, similar to, but not the same as amber. At present, the most important localities for bauxite deposits in Hungary are those of the Cretaceous-Eocene bauxite deposits in the Bakony. Bauxite has been mined since the 1920's and for decades it has been the chief raw-material of the Hungarian aluminium processing industry. Our karst-bauxite reserves are of considerable importance on a European scale but they cannot compete with the extensive surface deposits of laterite-bauxite of the Tropics - which are much more easily and cheaply produced - so that the future of Hungarian bauxite mining is uncertain. In the Bakony and at other Transdanubian