Quartz

SiO2 - Mohs Hardness: 7.  Rock Crystal is the name given to all clear colorless quartz. It is widely used as a popular ornamental stone and is also used as a gemstone. Although it is one of the least expensive gemstones, cut rock crystal has been used as imitation diamonds. The most common use for rock crystal is in ornamental carvings. A well known ornamental carving for rock crystal is the crystal ball of fortune telling fame.
Abstract/Description: SiO2 - Mohs Hardness: 7. Rock Crystal is the name given to all clear colorless quartz. It is widely used as a popular ornamental stone and is also used as a gemstone. Although it is one of the least expensive gemstones, cut rock crystal has been used as imitation diamonds. The most common use for rock crystal is in ornamental carvings. A well known ornamental carving for rock crystal is the crystal ball of fortune telling fame.
Subject(s): Arkansas, United States
environmental sciences