The 3 most used instruments in looking at colored stones. Check almost 85% of all colored stones using these instruments. For more help try getting the book "Gem Identification Made Easy". All 3 items included. Gemoro Hastings triplet loupe 21mm 10X: Our best seller just became better with the National Jewelers Supplies logo added. 21mm 10x. This is the power used when labs are grading diamonds and jewelry. Our precision, high quality 10x 21mm Hastings Triplet Loupes have an excellent magnification, superior Hoya Japanese optics, three bonded aplanatic and achromatic color corrected lenses. Dicroscope: Shows whether or not a stone is dichroic (reflects 2 colors). Made with calcite for long lasting use. Protective leather carrying case included. Chelsea Filter: Helpful in identifying certain red- blue and green stones. Used to determine whether a stone is natural or synthetic. Can also be used for detecting synthetic blue Spinel and detecting dyes in certain gems. Made in Great Britain.