Kul'chets'ka G. Volatile components of minerals as indicators of mineralogenesis

The work encompasses the results of mineralogical research based on chromatographic analysis of gaseous pyrolysis products of minerals and mineral paragenesises and the study of single fluid inclusions in minerals. Pyrolysis gas mixture at 50 - 1050°C temperature range is supplied from three sources. The sources are: physically adsorbed gases, fluid inclusions and chemical groups in crystal. Their vaporization temperature depends on the type of volatile components source. The pyrolysis technique allows to estimate volume, chemical composition and location of volatile elements in minerals. In addition to fluid inclusions and structural chemical groups, minerals contain volatile elements as impurities. The most widespread of them are hydrogen and carbon atoms. Opal, glauconite and quartz textures are effected by volatile trace elements. Hydroxyl, carboxyl, hydrocarbon and carbonate groups located on the single crystal surface prevent silica polymerization and contribute to formation of grainy and porous morphological mineral varieties. There also exist some solid solutions of volatile impurity atoms and vacancies in mineral. During the diagenetic stage of mineral compaction some fluid and mineral diagenetic inclusions can appear as a result of disintegration of those solid solutions. Gel inclusions that were found in opal, prove the immiscibility of acid and alkaline types of silica gels. Discrete portions of volatile components, evolved from a mineral in the process of the step-by-step heating form gas-pyrolysis spectrum, which is the typomorphic sign of mineral. Volatile components' composition is predetermined by conditions of mineral formation. The spectrum of individual mineral is less informative than that of mineral paragenesis. Temperature, oxygen potential, acidity, lithostatic and fluid pressure, as well as the type of system, cause the vaporization curve shape