3421 x 2814 px | 29 x 23,8 cm | 11,4 x 9,4 inches | 300dpi
Aufnahmedatum:
5. Dezember 2007
Weitere Informationen:
Amethyst is the purple variety of quartz (SiO2), containing an impurity of iron, which gives the violet color to the mineral. The hardness of the mineral is the same as quartz's, thus it is suitable for use in jewelry. Amethyst occurs in primary hues from a light pinkish violet to a deep purple. Amethyst may exhibit one or both secondary hues, red and blue. Synthetic amethyst is produced by gamma-ray, x-ray or electron beam irradiation of clear quartz which has been first doped with ferric impurities. On exposure to heat, the irradiation effects can be partially cancelled and amethyst generally becomes yellow or even green, and much of the citrine, cairngorm, or yellow quartz of jewelry is said to be merely "burnt amethyst".
