Silica(quartz); Silica(quartz) is a colorless crystal like beryl. The silica(quartz) come in different colors, such as yellow(citrine), smoky, and purple(amethyst). The color changes because of transition-metal impurities. Silica, a white to colorless crystalline compound, is usually in the form of quartz.
Silica, Quartz is an odorless, colorless, white or reddish crystalline (sand-like) solid. It is used in making glass, ceramics, and other Silica containing products, and as an abrasive and filtering agent.
The silica minerals when pure are colourless and transparent and have a vitreous lustre. They are nonconductors of electricity and are diamagnetic. All are hard and strong and fail by brittle fracture under an imposed stress.
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2.