Material	λ (nm)	n
Vacuum		1 (by definition)
Air at STP		1.000277
Air	589.29	1.000293
Carbon dioxide	589.29	1.00045
Helium	589.29	1.000036
Hydrogen	589.29	1.000132
Arsenic trisulfide and sulfur in methylene iodide		1.9
Benzene	589.29	1.501
Carbon disulfide	589.29	1.628
Carbon tetrachloride	589.29	1.461
Ethyl alcohol (ethanol)	589.29	1.361
Silicone oil		1.336-1.582
Water	589.29	1.3330
10% Glucose solution in water	589.29	1.3477
20% Glucose solution in water	589.29	1.3635
60% Glucose solution in water	589.29	1.4394
Titanium dioxide (Rutile phase )	589.29	2.496
Diamond	589.29	2.419
Strontium titanate	589.29	2.41
Amber	589.29	1.55
Fused silica (also called Fused Quartz)	589.29	1.458
Sodium chloride	589.29	1.544
Liquid helium		1.025
Water ice		1.31
Cornea (human)		1.373/1.380/1.401
Lens (human)		1.386 - 1.406
Acetone		1.36
Ethanol		1.36
Glycerol		1.4729
Bromine		1.661
Teflon AF		1.315
Teflon		1.35 - 1.38
Cytop		1.34
Sylgard 184 (Polydimethylsiloxane)		1.4118
PLA		1.46
Acrylic glass		1.490 - 1.492
Polycarbonate		1.584 - 1.586
PMMA		1.4893 - 1.4899
PETg		1.57
PET		1.5750
Crown glass (pure)		1.50 - 1.54
Flint glass (pure)		1.60 - 1.62
Crown glass (impure)		1.485 - 1.755
Flint glass (impure)		1.523 - 1.925
Pyrex (a borosilicate glass)		1.470
Cryolite		1.338
Rock salt		1.516
Sapphire		1.762–1.778
Sugar Solution, 25%		1.3723
Sugar Solution, 50%		1.4200
Sugar Solution, 75%		1.4774
Cubic zirconia		2.15 - 2.18
Potassium Niobate (KNbO3)		2.28
Silicon carbide		2.65 - 2.69
Cinnabar (Mercury sulfide)		3.02
Gallium(III) phosphide		3.5
Gallium(III) arsenide		3.927
Zinc Oxide	390	2.4
Germanium		4.01
Silicon	590	3.962