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CRYSTALLOMORPHOLOGY OF DIAMONDS IN KIMBERLITESL

V. S. Shkodzinsky

Diamond and Precious Metal Geology Institute, SB RAS, Yakutsk, Russia

The obtained evidences indicates that kimberlites were formed from high-pressure (8 GPa) residual liquors of the fractionated peridotitic layer of magmatic ocean. Diamonds originated as a result of an increase in the concentration of carbon due to a decrease in the amount of residual liquor during the crystallization of magmas. Due to the still high temperature of the upper parts of the early magmatic ocean, the cooling and crystallization of its bottom layer at first occurred very slowly and for a long time. This caused the formation of giant diamonds and explains their predominantly octahedral cut.

Keywords: diamond, kimberlites, accretion, magmatic ocean, fractionation.

DOI 10.20403/2078-0575-2023-3-122-130

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