Some rhinestones are actually made of crystal, while others are made of acrylic or glass.
Some people call rhinestones "the poor woman's crystal," says Oriella Stillo, owner of Accessity in Toronto, but the difference between the two stones is not that clear-cut. Duncan Parker of the Harold Weinstein Gemological Laboratory in Toronto explains that what's special about a rhinestone is its metal or foil backing, which reflects light and makes the stone glitter. Crystal, on the other hand, has no backing and is always made of glass, often with chemical additives (such as lead) that give it extra sparkle.
