High accuracy: Professional gemstone refractometer has high accuracy, small size, easy portability and simple operation. Specially developed: This refractometer is specifically designed to measure the refractive index of gemstones and materials. Strong practicability: The main application of the portable gemstone refractometer is to measure the angle at which light is bent or refracted by the stone. Easy to read: The jewellery gemstone refractometer has a highly visible display for easy reading. Quick identification: The refractometer can quickly and accurately identify a variety of single and double gemstones and helps to identify diamonds, moissanite, etc.