Fused silica is produced by melting high purity natural silica sand(quartz sand)  at 2000 degree Celsius.In the fusing process, the crystalline phase of silica sand transforms into amorphous phase fused silica.  After cooling, Fused silica ingot  is made out with high purity amorphous silicon oxide. Fused silica ingot is separated into 5-10cm lumps Grade A, Grade B and Grade C according to the black point size.
Because fused silica has a very low thermal conductivity and excellent thermal shock resistance, fused silica has been widely used kinds of industries, such as investment casting, refractory, technical thermal ceramic, epoxy modling compound, fusion bounded epoxy FBE powder coatings.