Q. How to find out lamp is a crystal lamp?

Answer

If it's made of crystal you'll be able to hear a soothing tone emanating from inside it. Examine the level of crispness or smoothness of the cut with your most attentive gaze. The smoother something is the greater the likelihood that it is made of crystal. Crystal on the other hand has a rim that is much thinner than the rims of normal glass. You may also see it by staring at it under a bright light or by doing so while standing in the sunlight. Crystals have the ability to split light up into its component colours much like a prism.