New Approaches to the XRD Studies of Complicated Crystal Chemical Phenomena in Minerals

The crystal Chemical phenomena (e.g. polyhedral stacking variations, microtwinning, modulation, etc.), which accompany the formation of real structures, are considered on the basis of the most recent structural studies of a large group of silicate minerals and their synthetic analogues, e.g. raite, vuorijarvite, haiweeite and synthetic K4(NbO)2[Si8O21]. The new approaches used for their investigation allowed extension of the Scientific ideas connected with the structural systematics of minerals, the forms of concentration of Chemical elements in the Earth’s crust, further development of modular theory and with other problems of modern structural mineralogy