Color Changes in Diamonds during Their Processing into Cut Brilliants: System Analysis and Experimental Studies. — Moscow, 1991. Speciality 04.00.20 — Mineralogy, Crystallography.

Nona D. DronovaColor Changes in Diamonds during Their Processing into Cut Brilliants: System Analysis and Experimental Studies. — Moscow, 1991.Speciality 04.00.20 — Mineralogy, Crystallography.Author’s abstract of the dissertation for the degree of Candidate of Geological and Mineralogical Sciences. Abstract:This dissertation investigates the mechanisms and patterns of color changes in gem-quality diamonds during processing into cut brilliants. The research emphasizes the significant influence of technological treatment regimes—beyond the properties of the rough crystal—on the final quality, color, and market value of brilliants. The study identifies correlations between initial crystal characteristics and resulting changes in optical properties, especially color, during processing. Special attention is given to the role of color centers, their redistribution, and interaction with other structural defects under different mechanical and thermal regimes. More than 2,000 diamond crystals from a Yakutian deposit were examined, along with corresponding cut brilliants. A comprehensive set of methods was employed, including optical spectroscopy, infrared microscopy, microphotometry, luminescence measurements, and electron microscopy. The research outcomes include: Statistical analysis of physical properties of rough and processed diamonds; Identification of technological parameters affecting color stability; Models for process optimization to minimize undesirable color changes; Methodologies for calculating contact temperatures during cutting and polishing; Recommendations for production to maintain and enhance diamond color quality. The results have practical significance for diamond cutting enterprises, contributing to optimization of manufacturing processes and increasing the market competitiveness of brilliants.