COLOR ALTERATION IN GEMSTONES THROUGH VISIBLE LIGHT, HIGH TEMPERATURE AND UV EXPOSURE

Historically several gemstones have been termed “evening stones” because of their propensity to loose or alter their color after exposure to various environmental stimuli. Our research will use xrf and visual examination to test various factors prior to and after alteration to make recommendations for ensuring stability in selected gems and mineral specimens in both private wear and museum exhibit conditions. The selected specimens include the quartz varieties amethyst and rose quartz and spodumine variety kunzite from sites in Morocco, North America, Brazil, and Pakistan. Preliminary xrf analysis shows elemental differences between rose quartz from Morocco and North America, and amethyst samples from Morocco and Brazil. The significant differences in the elemental percentages are of chlorine, chromium, and nickel.