Gemological Gem/Gemstone Refractometer/Tester Refractoscope, Gemmological instrument, Gemology Tool , ... Gemmological instrument,Gemology Tool ,Gemological instrument-----------------------------------------------------------------Gem Tester Refractometer is one of most important optical parameter. ... , black color, C/w mini flashlight, 2ml RI liquid, manual; One year warranty Measuring range Refractive ...