You probably can use other tests besides the UV lights, but they are convenient and easy to use…just don’t shine them in your eyes. I would not buy either of the Gem A lights, since there is a portable, battery or mains powered Raytech Versalume available for $99. I think you can also find various LW sources for cheap and there are now a number of sanitizing SW lights available as wands…one I looked at was 270-280 nm, which is within the SW spectrum for gemology. Another was 254 nm and it was a portable wand for only $5.49 on Amazon. The LW UV flashlights are $10 to $20 on Amazon. Just try to get one that does not put out a lot of blue/violet light…read the reviews and buy something returnable. Then test both the LW and the SW with known minerals/gems to see if you get the reaction you are expecting. They do tell you what wavelength the lights are, but merchants have been known to lie…I have the Versalume, but if I didn’t, today I would probably go with a couple of the cheap flashlights/wands. At the current prices, they are worth getting. Things are a lot different now, with cheap Chinese instruments, than they were in the 90’s when I got my GIA cert. Then the best I could do for a refractometer was $400 for a used duplex. Made my own dichroscope out of a film can, a lens and a piece of calcite. Finally located a stereo microscope in Brooklyn from an old gentleman for $350. Ebay and China changed all that. You can put together a set of instruments for $200-$500. At that time, we didn’t even know anything about magnetism, but now you can equip yourself to use that for $20 or so… -royjohn