There are two types of quartz glass, transparent and opaque quartz glass. Transparent and opaque quartz glass are materials with economic value used in industry and scientific research. The raw materials used in its manufacture (using smelting method) are crystal or high-purity, ultra-high-purity quartz sand (transparent quartz glass) and white quartz sand (opaque quartz glass). These two raw materials exist in nature, and its composition is composed of very pure SiO2.
Quartz glass and crystal have the same chemical composition, but are very different in structure. One is glassy and the other is crystalline. Crystal cannot withstand high temperature thermal shock, it will break and transform into other crystal metamorphosis when it encounters high temperature, while quartz glass can withstand extremely high temperature shock. The manufacture of transparent quartz glass and opaque quartz glass requires high temperature, because crystalline SiO2 can be melted above 1713°C.