The development of mineralogy, the evolutionary changes in compre­ hending the mineral substance of the earth are closely associated with the progress of research methods. Over a space of more than two and half centuries, from the goniometry of the mineral crystals to microscopic petrography and optical mineralogy, to crystal structure determinations, electron micros­ copy and electron diffraction and finally investigations into their electri­ cal, magnetic and mechanical properties, all this has led to the formation of the existing system of mineralogy, its notions, theories and to a proper description of minerals. However, no matter how great the variety of methods employed in mineralogy, they all come to a few aspects of substance characteristics. These are methods of determining the composition, structure and proper­ ties of the minerals. Thus the X-ray micro analyzer, the atom-absorption, neutron-activation, chromatographic and other analyses open up new opportunities for determining nothing else but the elementary com­ position of minerals.