How does a Refractometer work?
Refractometer works on the principle of Total Internal Reflection i.e. when light travels from denser material or the material with higher refractive index to rarer material or the material with lower refractive index, the light reflects into the denser material or refracts into the rarer material depending on the angle of incidence of the light traveling. (image courtesy: www.diamondtech.com). Refractometer is made of a metal case, polarizing filter on the top, glass hemicylinder and viewing lens at the bottom. Natural or white light is passed through the back of the unit. The light travels through the glass hemi cylinder and then to the gemstone which is placed on the glass hemicylinder using a special refractive index liquid, which seals the gemstone to the hemicylinder thereby removing the air in between them. This is done to maintain the same speed of light in both the glass hemicylinder as well as stone so that the refracted rays obtained are accurate. The light is then refracted
