Ratio of structural impurity distribution in diamond crystals and kimberlite pipe diamond potentiak (case study of Arkhangelsk region and Yakutia)

IR spectroscopy was used to compare diamonds from 12 pipes, Arkhangelsk region. Based on positive correlation between average N and H values in diamonds from various deposits, it was found that crystals from low-grade diamond pipes are relatively enriched in hydrogen compared with diamonds from Lomonosov and Grib deposits. In terms of structural impurity distribution, Arkhangelsk deposit diamonds differ from Yakutian diamonds; it could be due to various composition of compared diamonds’ source matter and thermodynamic conditions of their growth. It is shown that hydrogen is a negative factor of diamond potential in both Yakutian and Arkhangelsk diamonds. This can partly be explained by impuri-ty blocking effect on diamond crystal growth.

Особенности структур распада твердого раствора Cu-Ag cульфидов на месторождении Теплое (Северо-Восток России)

The authors consider features of the triple structure of Ag-Cu-S solid solution decomposition resulted from redistribution of matter in the ores of the epithermal Au-Ag Teploye deposit due to the spatial combination of volcanogenic Au-Ag mineralization, with relatively later copper porphyry. The discovery of the mckinstryite, copper-silver sulfide, permits to consider the occurrence of copper in acanthite a non-structural impurity element, while the term "cupreous acanthite" appears insufficiently substantiated. It has been suggested that the mckinstryite-jalpaite (+ acanthite) structure was formed not by the decomposition of a solid solution or the crystallization of a normal hydrothermal solution, but but in the course of solidification of the sluggish, viscous, colloid-like substance in a metastable environment under low-temperature conditions, and was accompanied by structural rearrangement of its mineral constituents.