Rare natural color change alexandrites glow in 14K white gold studs. Different types of light cause the unique color change effect. Under incandescent lights it is more purple, while in the sunlight or fluorescent lights, it is more blue. (The photos show the colors in both lighting styles.) This particular set of alexandrites was mined from Fire Creek Mine (Corrego do Fogo) in Brazil. They are 0.42 ct total weight with a round cut approximately 3.5 mm in diameter. The settings are 4 prong basket style with standard friction posts and backs.