... Clear Quartz Plate Application: Optical Thickness: 0.5-20mmShape: Round, Square, Rectangular Place of Origin: Jiangsu, China Brand Name: ... >90%Low Thermal Expansion CoefficientBoth side polishedFlame Polishing, optical polishing, grind, general polishing. Two sides polishing; ... used in scientific research, medical, electronics instrument, optical industry etc.3. Shape Round, square, rectangular and ...