Gem Emerald Gemstone Refractometer Instrument Jewellery Tool For Gemstone Identification

Australian supplier, can deliver in 1 to 3 days in Australia if needed !!! RHG-181 Description   Gem Refractometer Gem Instrument Jewellery Tool Professional Gemstone identification Built-in LED Light Emerald Testing Tool The gem refractometer uses a high refractive index lead glass as the test prism; Measuring range: 1.30-1.81, accuracy: ± 0.002, power supply device: built-in LED lamp with three button batteries; Professional optical design and built-in narrow wavelength quasi monochrome LED light source make the shadow boundary ultra straight and clear; The black background high contrast ruler makes the interface clearer; It is equipped with 3ml refractive oil (refractive index 1.78), and is packaged with leather cases, which are elegant in appearance. Note: The refractive index of diamond is 2.417, so it cannot be measured. Operating Steps ① Select a polished plane to wipe, and make a recognizable direction (such as the long axis direction) of the gem parallel to the long axis direction of the refractometer measuring platform, and drop a little contact oil on the measuring platform;② Observe the shadow boundary through the eyepiece. In general, two close shadow boundaries can be observed. In order to enhance the observation effect, the polarizer in the instrument accessories can be used. Place the polarizer on the eyepiece and rotate it. When it is turned to a certain position, one shadow boundary disappears, and the remaining one is particularly clear. At this time, record the scale value of the shadow boundary; Then rotate the polarizer to make the original shadow boundary disappear, while the shadow boundary that has read the scale disappears. At this time, record the scale value of the new shadow boundary. Therefore, during this operation, a pair of refractive index values can be obtained;③ Repeat step ② for every 45 ° rotation of the gem. At each position, a pair of refractive indexes can be measured until at least 4 groups of data are measured;④ The minimum and maximum values of these data, as well as the difference between them, are selected as the minimum refractive index, maximum refractive index and maximum birefringence of the gem. Specifications: Range: 1.30-1.81ri Minimum Graduation: 0.01ri Size: 62x32x130mm Includes: 1 x Gem Refractometer 1 x Flashlight 1 x Refractive oil 1 x Instructions