Amethyst is one of the most abundant crystals in the world, but the most prized pieces can cost almost a million dollars. Some of the world's largest amethyst geodes come out of Artigas, Uruguay.

Rosie is a freelance writer living in London. She has covered everything from ancient Egyptian temples to exciting medical breakthroughs, but she particularly enjoys writing about wildlife ...

(At one time, amethyst was also considered a precious gem, but large reserves were later found in Brazil, reducing its value.) Precious gems are formed in different ways and composed of different ...