Take a century-old glass bottle, and expose it in the desert to the ultraviolet radiation present in strong sunlight. Come back after ten years, and the glass will have acquired an attractive purple color. Heat the bottle in an oven, and the color disappears. read more
Amethyst is a purple variety of quartz (SiO 2) and owes its violet color to irradiation, iron impurities (in some cases in conjunction with transition element impurities), and the presence of trace elements, which result in complex crystal lattice substitutions. read more
Amethyst, topaz and smoky quartz-gemstone colors arising from color centers Quartz may be the second most common mineral on our planet’s crust, but everyone from the ancient Egyptians and Australian Aborigines to modern-day New Age practitioners believe that this crystal holds mystical or healing properties. read more