Rock Crystal or Crystal Quartz beads are the colorless species of Quartz composed of pure SiO2. The name comes from the Greek word for `ice` as it was believed that rock crystals were frozen eternally. Crystal Quartz is commonly included with needles from neighboring elements such as goethite (star quartz), gold, pyrite, copper, rutile and tourmaline. One of the most brilliant quartz varieties and sometimes used as a diamond substitute. The gem is mined in Brazil, Africa, South Africa, Uruguay, US, Canada, India, Madagascar, Mexico, Myanmar (Burma), Namibia, Sri Lanka and Tanzania.