Gemmological Refractometers are used to measure the Refractive Index of gemstones, as well as the index double Refraction. Through the parameter you can judge whether a gem is uniaxial or biaxial photo-positive or photo-negative.
RGM-900: Proffesional Gemmological Refractometer 1.30 to 1.81 RI ± 0.02 (no illumination)
RGM-600I LED: Gemmological Refractometer 1.30 to 1.81 RI ± 0.02 (LED illumination)
RGM-700: Gemmological Refractometer 1.30 to 1.81 RI ± 0.02 accuracy with LED illumination built in.
RGM-RIoil: Index oil RI 1.79 3ml(10g) bottle
RGM900 brochure:RGM-900.pdf