... quartz plate,rectangular quartz plate,quartz panelUsed for window material,mask substrate or heat insulation,optics,electronics ... .Characteristics:1.high purity,2.low coefficinet of thermal expansion,3.temperature resistance,4.corrosion resistance,5 ... optical transmission >90%6.No bubble, no airline Thermal propertiesStandard value Transformation point1280°cSoftening point1780°cAnnealing point1250° ...