MiniMAX™ UV-5NF UV Lamp Shows and Tells

One of the easiest and quickest ways gem dealers and gemologists can determine if a stone has been heat-treated is with ultraviolet (UV) fluorescence. Now there is an affordable tool that can help make a first determination.

The MiniMAX™ UV-5NF is a battery-operated, 5-watt UV lamp that is powerful, portable and extremely practical because it provides both long-wave (365nm) and short-wave (254nm) UV in a lightweight, compact unit. It is powered by four 1.5-volt AA alkaline batteries (not included) and includes an AC adapter, nylon carrying strap and convenient travel pouch.

Under magnification, the lamp’s short-wave UV will display chalky fluorescence in heat-treated rubies and sapphires. Although the color of these chalky segments may be similar to the gem being tested, they will appear lifeless or dull. Since fissures in emeralds are often enhanced with oils and resins, many of these will fluoresce under the lamp’s filtered long-wave UV light. Under the lamp and magnification, the treated segments show entirely different colors from the rest of the gem.