optical quartz glass plates are with high clear color, and polish them, if client need Specification:Material: JGS1, JGS2, JGS3Tolerance: +/- 0.1mmThickness: Upon requirementsurface: 40/20, 60/40, 80/50Form: circle, square, ellipse, or upon requirement Quartz glass has some excellent characters, such as high temperatura resistance, low coefficient thermal expansion, good chemical stablity, good ...