SE MJ3621L-10x Loupe - LED Illuminated, 10X, 21mm in Plastic Case

10 x 21mm Glass Magnifying Loupe Magnifier Jeweler Eye Jewelry Pocket Loop Case

Jewelers Loupe Led + UV Lights Triplet iGaging 21mm Lens 10X Magnification Jewel

L3000AC - Deluxe -L E D- Jewelers Loupe 10x 21mm ( mj3621l )

L3078B - Premium 10X Magnifier Loupe 21mm with Rubber Sleev

SE MJ3621L-10x Loupe - LED Illuminated, 10X, 21mm in Plastic Case

Jewelers Loupe Led + UV Lights Triplet iGaging 21mm Lens 10X Magnification Jewel

The light is used for checking fluorescence in diamonds. Diamonds with fluorescence will appear cloudy when viewed with the light on. Fluorescence is not 'diagnostic' but, as with most tests, it eliminates some possibilities, opens other possibilities, suggests which other tests to carry out, and that's how gemologists identify stones.

21mm Jeweler Loupe 10x Magnifier with LED and UV Light

L3000AC - Deluxe -L E D- Jewelers Loupe 10x 21mm ( mj3621l )

MAXIMIZE Gold Jeweler's Loupe, 10X Magnification, 21mm Triplet Lens, Swivel Case

L3032T - 10x21MM Triplet Professional Jeweler's Loupe, Leath

10 x 21mm Glass Magnifying Loupe Magnifier Jeweler Eye Jewelry Pocket Loop Case

L3326A - 10X Power Lighted Loupe ( mg2130-led mj362530lb ) h