Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz, traditionally called rock crystal or clear quartz, is colorless and transparent or translucent, and has often been used for hardstone carvings, such as the Lothair Crystal. Common colored varieties include citrine, rose quartz, amethyst, smoky quartz, milky quartz, and others. Quartz occurs in several varieties, citrine, amethyst, praseolite, rosequartz, tourmalated quartz, etc.
CHEMICAL COMPOSITION: SiO2
COLOR: Very light pink to medium-dark pink
REFRACTIVE INDEX: 1.544 to 1.553
SPECIFIC GRAVITY: 2.66 (+0.03/-0.02)
MOHS HARDNESS: 7