Lead crystal is a type of glass that contains lead oxide, which enhances its clarity and brilliance. The addition of lead gives the glass a higher refractive index, allowing it to sparkle more than regular glass. This quality makes lead crystal popular for decorative items, such as vases, glassware, and chandeliers. To be classified as lead crystal, the glass must contain at least 24% lead oxide. This composition not only improves its appearance but also makes it heavier and more durable. However, due to health concerns regarding lead, many manufacturers now produce alternatives, such as crystal glass, which do not contain lead.