When browsing for the perfect chandelier, it helps to know whether glass or crystal will better fit the decor of a room. Generally, crystal chandeliers give off more color, but the fundamental difference between glass and crystal is the lead content. In the U.S., glass with 1 percent of lead or more is deemed a crystal, while in Europe glass becomes a crystal only when lead content exceeds 10 percent.
Lift each piece in your hand to determine the weight. Lead content can vary in a crystal from 1 percent to 40 percent. Either way, lead is dense and will add more weight to the glass. The crystal piece will be heavier.
Look at each piece closely. The clearer piece will be the crystal piece, on account of the lead inside. An increase in lead content leads to more clarity in the crystal.
Hold each piece up to the light. White light passes through the plain glass, while lead allows more light to pass through the crystal and maximizes diffraction, thereby creating a dazzling spectrum of light that is easily recognizable.
Note the body of the chandelier from which the pieces were pulled. If the frame is brass, copper, bronze, or iron, the chandelier is most likely crystal, because its weight requires the body to be robust.