Holiday Return/Exchange Policy: For customers who purchase between now to December 25th, we will automatically extend the return/exchange date to January 31st. No restocking fee, no question ask, hassle free return. 

Limited time promotion, price just reduced from 102.64 dollar you can't find a better deal for this price 93.39 dollars . If you are not sure about this item, please check our feedbacks and the over 300 sold history. No other seller sold more than we did.    We have more in stock, Larger quantity welcome!   USPS Priority Mail shipping, get it fast!     This item is commonly known as Gemstone Refractometer, is the primary and most powerful tool in identifying and authenticating polished precious and semiprecious gemstones and also observing the optical properties and the structure of gemstones. This model is just as good as the expensive models used in gemological institutes, it has a built-in light source and with the aid of the Contact liquid (RI Fluid), which creates an optical contact between the glass and the gemstone, you can measure or test the Refractive Index of faceted stones, its 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). This product offers you the worry-free, light and easy way to identify and/or authenticate your most precious gemstones. Buy Now!

Features: Convenient & easy to carry With 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 and very reliable Two color available, black and light grey. Black color will be the default color to ship.   Specifications: Measuring Range: 1.30 – 1.81 RI  Minimum Graduation (RI): 0.01 RI  Illumination: Internal illumination with momentary switch(Standard wavelenth 589nm) Size: 30mm x 70mm x 130mm  Scale Division: 0.01 nD  Weight: 0.4 kg  Ranges of Application: Laboratory, Gemology Filter: Polarizing filter  Power Source: 1.5V x3 button batteries  Made of durable heavy metal and scratch proof glass Operating Information: Open the upper cover then wash the gem and prism with alcohol. Lay the instrument on the worktable. Drop a little bit of special refractive oil onto the surface of prism and press it by a thin glass bar. (Be sure not too much or too little)  Make sure the ground surface of gem to be measured is close to the prism, press it again lightly, let the refractive oil be evenly distributed between the two surfaces then close the upper cover.  Press the light momentary switch, make sure that the internal light source is turned on when testing.  Move the eyepiece up and down and adjust the diopter accordingly. By this time you can see a light/dark boundary in the viewing field. The gradation (shade) on which the boundary located is called the refractive index of gem. Accessories included: 1.5V x3 buttom batteries Polarizer Storage Case  Refractometer Index Reference List (For more than 200 common gemstones, i.e. Calcite, Jadeite, Quartz etc.)  User's Manual               Warranty: 2 years

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