The crystallochemical research of the crystal structure and transformations of some Al, Mg-silicates from alkali, alkaline earth elements in secondary quartzite (Gedabek Ore Region)
Asgarov Rashad Gadim
2516.01 – Mineralogy, crystallography
At the result of the scientific researches in the North-East slope of the Lesser Caucasus is developed the mineral composition, located condition, genetic classification scheme of the secondary quartzite. Based on the experiments of the author and literary materials the comparative mineralogy was analyzed in the secondary quartzite. For the first time the feldspars are identified by the method of the X-ray analysis and the chemical composition of minerals are elaborated. Distribution regularity of Si4+ and Al3+ is arranged in the tetrahedral positions of aluminosilicates. For the first time mineral of muscovite 3H was found on the paragenetic association with dravite and was defined of the crystal structures of the minerals and other three more alkali, alkaline earth minerals. The structures parameters of the minerals were measured by using new auto-diffractometer APEX-II CCD with higher accuracy and calculated by the SHELXTL complex softwares.
Using the method of the comparative crystallochemistry, chemical composition data and elementary cells parameters of rhodezite-macdonaldite family minerals the structure of mauntainite is simulated. Calcium and sodium atoms create octahedric walls in the structure of mauntainite. Countinuos octahedric walls are connected on types of mountainite. It is probable that OH-groups are distributed in free vertices of tetrahedrons united with the octahedral layer.
In the study of the synthesis and transformation of minerals used simulation experiment and hydrothermal crystallization method. Three systems are investigated in the hydrothermal condition: dravite – NaOH (I); muscovite (3H) – NaOH (II); dravite + muscovite (3H) – NaOH.