Amethyst Cathedral with Calcite CrystalAn Amethyst cathedral is a Geode that is typically shaped like a church cathedral. Amethyst is a variety of Quartz that contains a few parts per million of iron. That is why it has the deep purple color you see here. Crystal home decor is a sparking accent to your space. Notice the beautiful white calcite growth within this geode. Geodes are usually formed in bubbles and other cavities inside volcanic rock, mainly molten rock that has joined other