... :1100C=2012FCharacteristics and superiority 1, Shape:Round, square, rectangle;2, optical silica sheet: ZS-1 ZS-2 HS / JGS1 JGS2 JGS3 ... . PurityTotal Impurities, including Al, Fe, Ca, Mg, Ti, Cu, Ni,Co, Mn, k, Na, Li, B<35ppmThermal DataAnnealing Point Strain Point ...