Both quartz and single crystalline alumina have a high temperature resistance, low coefficient of thermal expansion, good thermal shock resistance, excellent chemical stability and display good electrical insulation properties. They are also transparent for ultraviolet and infrared wavelengths, thus commonly applied in equipment used for the production of semiconductors, electric light sources, semiconductor communications devices, lasers, optical instruments, laboratory instruments, electrical equipment, medical equipment and chemical instruments; ranging from electronics, metallurgy, building materials and national defense industries.