Silica is a colourless, white, and has chemical compound. Silica is known as silicon dioxide or SiO2 because the name given is composed from silicon and oxygen. Silicon and oxygen is made up from silica because of common elements on earth. It is the main component of most sand and the primary ingredient in glass. Silica also make up the mineral called quartz. Pure silica is colorless, but if contaminants are present in a sample of quartz, it may be colored. For example, rose quartz is silica with trace amounts of iron and Milky quartz is simply silica with air bubbles or inclusions of liquid that make the mineral appear white.