ВЛИЯНИЕ ВЯЗКОСТИ РАСПЛАВОВ НА КРИСТАЛЛОМОРФОЛОГИЮ АЛМАЗА

Abstract

It is shown that degree of the media supersaturating by carbon, determining the crystal morphology of diamonds, depends mainly on SiO2 content and connected viscosity of kimberlite and lamproite melts, because coefficient of carbon diffusion is decreasing in million times together with increase of the SiO2 content. This concept is confirmed by the sharp decrease in amount of octahedrons and proportional increasing in quantity of rounded crystals and their II-VII varieties (by Yu. L. Orlov classification) along with rise of SiO2 concentration in magmatic rocks. Plotted diagrams allow to appraise a type of sources for diamond-bearing placers by the crystal morphology.