These crystals really shine, or should I say GLOW! That's right, they have our Art N' Glow Aqua glow powder! They are clear during the day, but put them under black light or charge them in the sun and they glow a brilliant blue. A perfect edition to your favorite crystal lover's collection! Just don't leave out in the sun too long. While my epoxy is sun damage resistant, that does not mean it can't happen. If you're going to charge them in direct sunlight, don't do it often for more than an hour at a time.