产 品 说 明                                                                                                                    

	Refractive Index	nF (486nm) = 1.4631; nd (588nm) = 1.4585; nC (656nm) = 1.4564
	Refliction Loss	for two surfaces at 400nm - 7.1%; at 588nm – 6.8%;
	Birefringence Constant	3.54 nm/cm
	Abbe Constant	67.8
	Bubbles/inclusions	None
	Fluorescence	Virtually fluorescence free
	Impurity Content	Total metallic impurities: less than 0.3 ppm
	OH- Content	< 0.2 ppm
	Density	2.201 g/cm3
	Coefficient of Expansion	0.55 x 10-6/oC
	Softening Point	1600oC (2912oF)
	Annealing Point	1120oC (2048oF)
	Strain Point	1025oC (1877oF)
	Max. Service Temperature	950oC (1742oF) - continuous 1200oC (2192oF) - limited time
	Dielectric Strength	250-400 kV/cm at 20oC
	Young's Modulus	73 GPa at 25oC
	Shear Modulus	31 GPa at 25oC
	Rupture Modulus	50 MPa at 25oC
	Bulk Modulus	36.9 GPa at 25oC
	Poisson Ratio	0.17 at 25oC
	Knoop Hardness	500 kg/mm2
	Compressive Strength	1.1 GPa
	Tensile Strength	50 MPa
	Molecular Weight	28.09
	Class/Structure	Amorphous glass
	Chemical Stability	High resistance to water and acids (except hydrofluoric).