The 3 most used instruments in looking at colored stones. Check almost 85% of all colored stones using these instruments. 1) Chelsea (Jadeite) Filter: An essential device in identifying colored stones. While it was originally intended to rapidly differentiate between genuine Emeralds and the pastes and doublets which resemble them, it also is a valuable aid in identifying other colored stones, as well. Designed to transmit only deep red and yellow-green light, and the best results are obtained when stones are examined under a strong electric light. Just hold the filter close to the eye with the stone or stones (for a number of stones can be examined at one time) receiving as much light as possible. 2) Jeweler's Loupe 10x Triplet Magnifier Lens : Made with precision, HEAVY DUTY, HIGH QUALITY and one of the most important tools used to inspect gemstones and other jewelry. With its special OPTICAL GLASS with 10x powerful magnification lenses, objects appear to be larger and reveal tiny details that couldn't seen with normal vision even the very smallest detail into sharp focus such as tiny crystals, trace minerals, grain surfaces, and microfossils. It comes with a Cushioned Sturdy storage case for protection and ease of carrying anywhere. 3) Diffraction Spectroscope Handheld spectroscope allows you to read a gemstone's spectral signature. How to use: view the colour of a gemstone, either by shining a light (pen-torch) through the stone into the spectroscope if the stone is transparent, or by viewing its reflected light if the stone is opaque. What you see: a spectrum (rainbow) which might be interrupted with black or white lines, it is the pattern of these lines you must learn to recognize. For the gemmologist: best at detecting iron and chromium. Brand New, ships within 1 business day.