10X Loupe, The Gemologists Best Friend International Gem Society Dedicated to bringing quality information and educational services to everyone interested in gemstones. French, German, Italian, Portugese and Spanish speakers click here . The simple hand loupe is the most valuable tool of the gemologist. You can learn more with it, and with greater ease, than any other instrument. Loupes come in several varieties.
Watch makers prefer the kind that are held by the eye socket.
There are loupes that are worn like eyeglasses, or those that clip onto your glasses. Some are illuminated, have built in tweezers and other fancy features. Ten-power magnification is the most useful for our purposes. Above that the depth of field, the area that is in focus, is so small that they become hard to use. A microscope is the best tool for higher magnification.