A MICROCOSM OF MINERALS: BOUNDARIES, OBJECTS, PROCESSES

摘要

The boundary line of a mineral microcosm is defined at the grain size of 0.1-0.3 mm. These values correspond to the bend f hyperbola curve on the diagrams 《Size vs. specific surface of grains》. The quantity of newly discovered microcosm minerals increases mainly due to the study of mantle-derived rocks, some exotic geological objects and the 《frozen》 chemical reactions products. The forming of microcrystals only is typical for minerals having layered structure with electroneutral slabs; but it depends also on kinetic factors of the substance crystallization. A peculiar part of the mineral microcosm is represented by the small-size clastic particles of natural or technogenic origin. Topochemical character of interaction between the small grains and a melt or a fluid results in their quite different chemical properties, in comparison to the macro-sized grains. Composition of intergranular substance, at the boundary between micro-particles of different minerals, doesn't correspond to the total chemical composition of the rock. Thus, the initial stages of metasomatic alteration of rocks are developing just according to the intergranular substance microchemistry. The lower boundary of the mineral microscosm cannot be defined precisely because of the polysomatism phenomena. The mere practice of the new minerals discoveries shows that the new mineral species couldn't be described demonstratively within particles smaller than 0.01 mm.