Infrared spectroscopy and internal structure of diamonds from the lchetju placer (the Middle Timan, Russia)

Vasiliev E. A., Petrovsky V. A., Kozlov A. V., Antonov A. V.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2017. V. 146. N 2. P. 58-72

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Language: Russian

Abstract

There was revealed in the «Ural’s» type diamond crystals from the Ichetju placer the wide range of equilibrium temperatures, which is typical for dodecahedron crystals from placers of the Urals, Brazil and North Yakutia diamondiferous provinces. Sheet plates, cut out from six rounded crystals, were investigated by infrared and photoluminescence spectroscopy, and cathodoluminescence methods. Octahedral zoning of growth layers dominates in internal structure of all studied dodecahedrons, and these growth layers are cut by the crystal surface. Cathodoluminescence (CL) images of all plates show surface spots of pigmentation. Concentration of nitrogen in Ichetju diamonds varies from 100 to 2200 ppm, and the B1 share of nitrogen defects varies from zero up to 100 %. The maximum absorption coefficient of the hydrogen band reaches 56 cm–1, while its average value for studied crystals is 0.8 cm–1.

Key words: IR-spectroscopy, cathodoluminescence, photoluminescence, diamonds, morphology of crystals, Ichetju placer.