Amethyst is a violet variety of quartz that has been used as a gemstone for many centuries and is a key economic resource in northern Uruguay. Geodes are hollow rock formations often with quartz crystals, such as amethyst, inside. Amethyst is a violet variety of quartz that has been used as a gemstone for many centuries and is a key economic resource in northern Uruguay. Geodes are hollow rock formations often with quartz crystals, such as amethyst, inside. Earth Sciences Phys.org – latest science and technology news stories
Geological surveys shed light on the formation mystery of Uruguay’s amethyst geodes
