Glossary of Terms

Refractive index

The amount of refraction that takes place in a particular substance, which is a direct connection to the speed of light in that substance. The higher the refractive index, the greater the amount of dispersion, which increase the brilliance of a material. The refractive indices of gemstones are measured with a refractometer, which can often identify them.
See Refractive Index in Mineral Properties for additional information.