Source: http://en.wikipedia.org/wiki/List_of_refractive_indices#List

List of representative refractive indices
Material λ (nm) n
Vacuum(by definition)   1  
Air at STP   1.000277  
Gases( at 0 °C and 1 atm)  
Air 589.29 1.000293  
Carbon dioxide 589.29 1.00045  
Helium 589.29 1.000036  
Hydrogen 589.29 1.000132  
Liquids(at 20 °C)  
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 (MIN-MAX)   1.336 1.582
Water 589.29 1.333  
Glucose solution in water(10%) 589.29 1.3477  
Glucose solution in water(20%) 589.29 1.3635  
Glucose solution in water(60%) 589.29 1.4394  
Solids at room temperature  
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  
Other materials  
Liquid helium   1.025  
Water ice   1.31  
Cornea (human)   1.373/1.380/1.401  
Lens (human) (MIN-MAX)   1.386 1.406
Acetone   1.36  
Ethanol   1.36  
Glycerol   1.4729  
Bromine   1.661  
Teflon AF   1.315  
Teflon (MIN-MAX)   1.35 1.38
Cytop   1.34  
Sylgard 184 (Polydimethylsiloxane)   1.4118  
PLA   1.46  
Acrylic glass (MIN-MAX)   1.49 1.492
Polycarbonate (MIN-MAX)   1.584 1.586
PMMA (MIN-MAX)   1.4893 1.4899
PETg   1.57  
PET   1.575  
Crown glass (pure) (MIN-MAX)   1.5 1.54
Flint glass (pure) (MIN-MAX)   1.6 1.62
Crown glass (impure) (MIN-MAX)   1.485 1.755
Flint glass (impure) (MIN-MAX)   1.523 1.925
Pyrex (a borosilicate glass) (MIN-MAX)   1.47  
Cryolite   1.338  
Rock salt   1.516  
Sapphire (MIN-MAX)   1.762 1.778
Sugar Solution(25%)   1.3723  
Sugar Solution(50%)   1.42  
Sugar Solution(75%)   1.4774  
Cubic zirconia (MIN-MAX)   2.15 2.18
Potassium Niobate (KNbO3)   2.28  
Silicon carbide (MIN-MAX)   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 (MAX-MIN) 3000 - 16000 4.05 4.01
Silicon (MAX-MIN) 1200 - 8500 3.48 3.42