Silicon Dioxide SiO2 powder refers to silicon dioxide powder. Silicon dioxide is widely present in nature and forms rocks together with other minerals. It is a white powder (completely pure silica) with the chemical formula SiO2, a molar mass of 60.1 g/mol, a density of 2.2, a melting point of 1650 (± 75) ℃, and a boiling point of 2230 ℃. Although silica is non-toxic, long-term inhalation can lead to silicosis.