RGM-900 Gem Refractometer 1.30-1.81RI

Item No.: RHG-900

RGM-900 commonly known as Gemstone Refractometer, is the primary and most powerful tool in identify and authenticate polished precious and semi-precious gemstones and observing the optical properties and the structure of gemstones. With the aid of Contact liquid (RI Fluid), that will create an optical contact between the glass and the gemstone, you can measure or test the Refractive Index of faceted stones, transparency or opacity, and its beauty, durability and scarcity. The refractive index (RI) of a gemstone provides the single most important piece of information to a gemologist seeking to identify an unknown stone. Due to its chemical composition and crystallization structure, each gem has a typical refractive index. In fact, you can also use this tool to measure R.I. for many minerals in crystal form as long as the crystals have a flat and polished face. Through these parameters, you can determine whether the gem is a Single Refraction (Isotropic) or Double Refraction (Anisotropic or Birefringence).

Key Features:

  • Heavy-duty and built to last
  • Convenient & easy to carry
  • Built-in Light Source that makes it a carry-and-use-it-anywhere device
  • Comes with Automatic Temperature Compensation (ATC) that let itself adjust to the climate
  • Approved by strict quality and safety standards, undoubtedly durable, very reliable and assures accurate testing results
  • Comes with 3 pieces AG13 batteries, carrying case, polarizing filter, index oil, index reference list and user's manual


  • Measuring Range : 1.30 - 1.81 RI
  • Minimum Graduation : (RI) 0.01 RI
  • Illumination : Internal Light Source with momentary/power switch
  • Dimension : 35mm x 63mm x 115mm
  • Scale Division : 0.01 nD
  • Weight : 0.4 kg
  • Ranges of Application : Laboratory, Gemology
  • Filter : Polarizing filter
  • Power Source : 3 x 1.5V AG13 button batteries
  • Color : Black

Accessories included:

  • One bottle of 1.800 Refractive Index Oil
  • Polarizing Filter
  • 3 pieces 1.5V AG13 Batteries
  • Carrying Case
  • Refractometer Index Reference List (For 77 common gemstones, i.e. Calcite, Jadeite, Quartz etc.)
  • User's Manual
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