Absolute Indices of Refraction List, Index of Refraction of Various Materials

Index of refraction of any material is strongly dependent on the wavelength (frequency) of light used to measure it. Standard index of refraction measurements are taken at the "yellow doublet" sodium D line, with a wavelength of 589 nanometers (509 THz).
MaterialIndex of RefractionState
Vacuum1(by definition)
Helium1.000036Gas(0°C and 1 atm)
Hydrogen1.000132Gas(0°C and 1 atm)
Air1.000277Gas(at STP*)
Air1.000293Gas(0°C and 1 atm)
Carbon Dioxide1.001Gas(0°C and 1 atm)
Liquid Helium1.025Liquid(at -270°C)
Water Ice1.31Solid(at 0°C)
Water1.330Liquid(at 20°C)
Acetone1.36Liquid(at 20°C)
Ethanol1.361Liquid(at 20°C)
Kerosene1.39Liquid(at 20°C)
Corn Oil1.47Liquid(at 20°C)
Glycerol1.4729Liquid(at 20°C)
Acrylic Glass1.490–1.492Solid(at 20°C)
Benzene1.501Liquid(at 20°C)
Crown Glass (pure)1.50–1.54Solid(at 20°C)
Plate Glass (window glass)1.52Solid(at 20°C)
Sodium Chloride (table salt)1.544Solid(at 20°C)
Amber1.55Solid(at 20°C)
Polycabonate1.60Solid(at 20°C)
Flint Glass (pure)1.60–1.62Solid(at 20°C)
Bromine1.661Liquid(at 20°C)
Sapphire1.762–1.778Solid(at 20°C)
Cubic Zirconia2.15–2.18Solid(at 20°C)
Diamond2.417Solid(at 20°C)
Silicon3.42–3.48Solid(at 20°C)
Germanium4.05–4.01Solid(at 20°C)

*STP is defined as a temperature of 273.15 K (0 °C, 32 °F) and an absolute pressure of exactly 105 Pa (100 kPa, 1 bar).