Silicon is one of the half metals, known as "silicon". The melting point is 1420 ℃ and the density is 2.34 grams per cubic centimeter. Hard and crisp. Insoluble in acid at room temperature, easy to dissolve in alkali. The properties of silicon metal are similar to germanium, lead and tin, and have the properties of semiconductors. Silicon in the Earth's crust is extremely rich in resources, next to oxygen, accounting for more than One-fourth of the total weight of the Earth's crust, silica or silicate forms. The purest silicon mineral is quartz or silica. Silicon has two kinds of allotrope: one is dark brown amorphous powder, the nature is lively, can burn in the air, another kind is the stable crystal (crystalline silicon).
General silica and quartz for glass and other building materials, high quality quartz for making alloys, metals and crystals