Industrial Grade Crystal Quartz Glass Rare Earth Polishing Powder Quartz glass is made from natural crystalline quartz (crystal or high-purity silica) or silicon compounds, which are melted at high temperatures in a clean environment. It has a series of excellent physical and chemical properties, such as good transparency, high temperature resistance, low coefficient of expansion, vacuum performance, corrosion resistance, etc., and is known as the "king of glass" in the