Amethyst geode (double) on black base

Amethyst from Brazil on black metal base. The largest source of Amethysts in the world is Brazil. This color appeared naturally after a process of irradiation, several million years ago: The iron chloride impurities contained in the crystal structure changed to become these purple silicates. The peculiarity of this piece is that two air bubbles froze nearby in the cooling lava of a volcano, then they received successive infiltrations that eventually crystallized into Amethyst. But one of the two geodes was more in contact with natural irradiation; which gave this bright purple. Only the matrix has been dark to increase the contrast with the power of violet. And this color is completely natural.