Keep a minimum of a good five car length from the car in front of you. You never know what other drivers are going to do or what could happen to you! If that feels too close or too far a rule of thumb is 1 second of following distance per 10 mph (16 km/h). That holds true especially in bad weather.
It is also found and mined in South Korea. The largest opencast amethyst vein in the world is in Maissau, Lower Austria. Much fine amethyst comes from Russia, especially from near Mursinka in the Ekaterinburg district, where it occurs in drusy cavities in granitic rocks. Many localities in south India yield amethyst.
Amethyst. The color of amethyst is the result of radiation damage to Fe 3+ in the interstitial site of quartz. The radiation could be due to gamma rays from 40 K. Current theory says that the ferric iron is oxidized to Fe 4+ by the gamma rays. Amethyst geodes in basalt near the town of Ametista do Sul, Rio Grande do Sul, Brazil. Amethyst geodes and citrine geodes (heated amethyst) for sale near Rio de Janerio, Brazil.