Gemstone Refractometer Gemology Gemologist RGM-800 Internal LED & Flashlight Gem

Item Description: RGM-800 Portable Combo Gemological Refractometer with a flashlight and LED internal light   COMBO LED INTERNAL LIGHT AND  OPTIONAL EXTERNAL SLOT FOR A FLASHLIGHT!   Comes with instructions!  Written by our staff, not converted from another language! Comes with a Gemstone Refractive Index Chart! Comes in a Blue Hard case! We were the first to sell these units on eBay!     Product Specs: Measuring Range :1.30 - 1.81 RI Minimum Graduation : (RI) 0.01 RI Dimension : 125mm x 70mm x 40mmScale Accuracy: 0.01 nD Weight : 0.4 kg Ranges of Application : Laboratory, Gemology Power Source : 3 x AG13 1.5V button batteries Illumination : Internal Light Source with momentary/power switch   One BRAND NEW RGM-800 Portable Gemological Refractometer in a Blue Hard Case. This handy little piece of equipment tests a gemstone's ability to slow down or bend light. The amount of slowing down it does to a beam of light is called the refractive index. THIS UNIT WILL HELP YOU DETERMINE WHI