Gemax Calcite Dichroscope, well calibrated & accurate results!!!
The dichroscope is a pocket-sized tool that can aid in the identification of gemstones. Calcite gives better results and is widely used by experienced gemologists. With plenty of experience, one could even positively identify some gemstones with the dichroscope alone (although confirmation tests should always be carried out).
This tool is used to inspect pleochroism in gemstones and to quickly separate some common stones from each other (such as ruby versus red garnet).