How can I tell real crystal from glass?

There are several ways to tell if an item is crystal or glass. The main difference between crystal and glass is that crystal is made with lead, making it easier to add decorative elements. Crystal refracts and disperses light, creating a rainbow effect, and is heavier than regular glass. When gently tapped, crystal items create a ringing, musical sound. If you are still unsure, consult a certified appraiser. Browse a range of authenticated fine crystal and glass pieces on 1stDibs.