Lead crystal is decorative glassware containing a minimum of 24 percent lead oxide. Known for its beauty and sparkle, lead crystal is commercially valued and often collected. Only glass products containing at least 24 percent lead oxide may be technically referred to as lead crystal.
The addition of lead oxide to molten glass causes the glass to be more easily melted and manipulated, cutting down on time spent working with the material. When added to molten glass, lead oxide provides a more clear and crystal-like appearance. After hardening, lead crystal is often hand- or machine-cut with facets. The facets look like crystals, leading to the transition from its original name, "flint glass," to the more-common "lead crystal."