Silver Mom, about the UV light, it's a hand held box about the size of a brick. Its a simple plug in with a strap on top to slip your hand into. There's a switch on top which changes it from long to short wave UV. This is very important because polymers and dyes often will not glow under one, but the other depending on the chemicals used. Almost all polymer will show up, (B jade) and most dyes. You want to put the bangle down on a counter top, like in the bathroom, with the main room light turned off. Then hold the UV light over the jade, but NEVER look directly into the light because it can damage your retinas! I have to ask my husband where he got his, but I know it was online, and it cost around $200. It's a great investment for checking your jade and any future jade purchases. For detecting dye, most gem labs do UV, then microscope and finally infared spectroscopy. But most dye will be detected by the first 2 methods. Under magnification, dye will be seen as faint, spider web like concentrations between the crystals within. If you have a bangle with VERY fine grain and thus microscopic crystals, Magnification may still be uncertain, so they do spectroscopy to be sure. If you want to know the brand name of the UV light, let me know and I'll get it.