The classification scheme for micaceous minerals is described. According to the size of mineral particles micas are divided into macrocrystalline compounds and microcrystalline clay micas. Macroc rystalline micas are differentiated into (a) Mg-Fe-Al micas, (b) Li-micas, (c) micas with other cations. Vertical boundary in the suggested scheme divides micas into trioctahedral and dioctahedral members. Additional subdivision is carried out on the basis of the extent of Si substitution in tetrahedral positions of their crystal lattice. Microcrystalline (<4μm) micas are subordinate to the crystallochemical scheme for macrocrystalline micas. List of mica species together with their varieties and synonyms is in Table 2., Karel Melka., and Obsahuje bibliografické odkazy
During the International expedition of the research vessel Dmitry Mendeleyev three sectors of the Western Pacific Ocean were studied: Philippine Sea, Solomon Sea and Coral Sea. From these areas also the samples for the orientation were taken in order to do the mineralogical examination with them. Above all, X-ray diffraction technique was used beside the chemical analysis performed by electron microprobe analyzer. Quantitative evaluation of min eral components was carried out applying X-ray diffraction. Standardless technique based on the adiabatic principle enabled th e quantitative determination directly from the X-ray diffraction diagram. Generally, sheet silicates - above all smectite, chlorite, mica (illite) - play the leading role in the mineral composition of collected samples of muds taken from the ocean floor. Besi des, also minerals of terrigenous origin are present: quartz prevailing mostly over feldspars (plagioclase > K-feldspar). Amphiboles and pyroxenes occured, but not everywhere. Carbonate minerals (calcite >> aragonite) were found only in samples from Coral Sea., Karel Melka, Ferry Fediuk and Anna Langrová., and Obsahuje bibliografické odkazy
Vermiculite in its macroscopic form occurs in the Archaean supracrustal rocks exposed towards east of Sargur supracrustal complex in Karnataka state. The present study forms the first detailed work on the occurrence of vermiculite associated with the ultramafic rocks in the Agasthyapura, which lies in the long. 76° 50’ 658” and lat. 12° 15’ 976”. Petrography, X-ray diffraction, FTIR, DTA&TGA, SEM, fluid inclusion and electron probe analyses are presented in this contribution study. The probable origin of vermiculite from biotite through hydrobiotite is discussed., Kikkeri N. Prakash Narasimha, Honnaiah Ramalingaiah, Karel Melka, K. Krishnaveni, Pinnelli S. R. Prasad, Chikkamadaiah Krishnaiah, Katihalli S. Jayappa and Atni V. Ganesha., and Obsahuje bibliografické odkazy