Gemmological refractometers are key instruments for research in gemological laboratories. Gemstones can be examined using the optical principles on which these refractometers are based.

• Portable, accurate and fast
  
• With dedicated optical filter

This table refractometer has been designed specifically for Determination of precious stones based on refraction index measurement. Contains a 590 nm filter for generation of monochromatic light

Gemmology:
One test for determining the identity of a gemstone is to measure the refraction of light within the gemstone. Every material has a limit value; above this limit value, light is reflected back internally. This can be measured and is therefore suitable for determining the identity of the gemstone. This is usually done with the aid of a gemmological refractometer.

Identification of the refractive index:
The refractive index, one of the most important properties in determining the type of gemstone, is a material constant that depends on the chemical composition of a substance. This allows users to identify gemstone materials by measuring the refractive index.
The refractive index is determined at the wavelength of the sodium D line (NaD) of 589 nm. This is filtered out of daylight using a special optical filter.

Range: 1.30 - 1.81 R.I.
Accuracy: 0.01 R.I.
With filter 590 nm