How can a refractometer be used to identify gemstones?

1 Answer
Apr 5, 2016


A refractometer measures the refractive index of a material, i.e. the amount of breaking of a ray of light. Of course the material has to be transparent.


All materials have a specific refractive index (#n#). For common glass this is in the neighbourhood of 1.5, special glass can have an #n# up to 1.9. Diamond is around 2.4.
By comparing the #n# of the material with the #n# of known gemstones, they can be identified or excluded.