This great new gemological refractometer has its special design features which can offer Built-in LED light and External Light Source (flashlight).
It can be used to measure the Refractive index of Gemstone or Ore, index of double refraction and identify/authenticate polished precious and semiprecious gemstones as well as observing the optical properties and the structure of gemstones, transparency or opacity and its beauty, durability and scarcity. It’s also used for measuring R.I. for many minerals in crystal form as long as the crystals have a flat polished face. Through the parameter you can judge whether a gem is uniaxial or biaxial photopositive or photonegative. It’s the very important instrument for jewelry market!
For more convenient using, this item has built-in LED light source, the LED can at least offer 10000 hours working! And also, the special design offers other way to get the light source if the built-in light source cant work; there is a light entrance in the back side and the built-in filter for external light source. A small torch as outside light source also included in the set without any extra cost!