Rock Lore & Tidbits: Quartz is the most common mineral on the planet. It is a component of a huge variety of rock types, and comes in an extensive range of colors and varieties. Chalcedony is a crypto-crystalline variety of quartz and includes the agate and jasper families. Many colors of quartz or formations have their own names, such as amethyst for purple quartz. The word quartz is thought to come from the German word "quarz", but the origin of that word is not known. The word crystal... comes from the Greek word "krystallos" which means ice. Ancient Japanese believed quartz formed from the breath of a white dragon, and regarded it as representing perfection.