Amethyst flower (Brazil)

This large 40cm diameter piece of Parma color is not exactly a flower, of course, but a group made of hundreds of quartz crystals. Usually they radiate from a central point, but here the air pocket in the lava of the volcano was so large, that there are several radiations. It is actually a pseudomorph of amethyst after calcite. It means that the amethyst, under certain temperatures, humidity, pressure... managed to replace the calcite crystals. Unusual, as Calcite crystals develop quite often in amethyst geodes, in a second crystalization. Beautiful contrast with the dark green basalt matrix, completely natural of course.