Check the listing for details. Gem Refractometer Gemological Gemstone W/LED Light &RI Oil Diamond Detector. Color: Black, Condition: New. Listed at 109.00 USD. Gem Refractometer Gemological Gemstone W/LED Light &RI Oil Diamond Detector Introduction: Gemstone refractometer index is a very important optical parameter. The gloss of the gem can be determined by this parameter.All kinds of gems can be determined according to the index of refractive index, because different gemstones have fixed refractive index.In addition, double refractive index can also be measured.This parameter can be used to determine whether a gem is a uniaxial crystal or a biaxial crystal.This kind of gem refractometer is small and light.Easy to carry, very popular in jewelry industry. Product features:1. Quick and accurate identification of single biaxial gems.2. Unique design, extremely low power consumption and easy to carry.3. Through strict quality and safety standard test, long - term failure service life.4. High quality and high accuracy measurement results. Product specifications:1. Measurement range: 1.30 ~ 1.81RI.2. Minimum dividing value: 0.01RI.3. Size: 30*70*130mm. Product packaging:1. Gem refractometer.2. The flashlight3. 3x1.5v button battery.（Not including internal）4. Refractive index reference.5. The instruction