Usage of Gemological Instruments

  • Refractometer: It is based on the principle of "total internal reflection". It is used to determine refractive index, optic character, optic sign and optic axis direction of gemstones.
  • Polariscope: It is used to find the optic character, optic figure and to detect pleochroism of gemstones.
  • 10x Loupe: It is used for diamond clarity grading, inspection of internal and surface features of gemstones.
  • Microscope: It is used to find minute inclusions and blemishes of gemstones.
  • Dichroscope: It is used to detect pleochroism and optic axis direction of gemstones.
  • Chelsea Filter: This instrument normally indicates the coloring elements present in certain green and blue color gemstones, namely emerald and spinel.
  • Spectroscope: This instrument helps in identification of gemstones by absorption spectrum and detects treatment like dyeing.
  • U.V. Lamp: It detects fluorescence and phosphorescence and helps to detect treatments done on the stones.
  • Reflectivity Meters: It is used to quickly determine refractive index of a gemstone.
  • Thermal Probe: This instrument is used to differentiate diamond from its simulant mainly from synthetic moissanite through head conduction process.
  • Advanced Techniques: These are some of the advanced instruments used to identify gemstone, treatments and source of its occurrence.