The main raw material in glass is silica (sand). To melt the silica into glass, a furnace must reach a temperature of approximately 2,600°F. Because of the presence of iron in sand, glass with a greenish color usually results. However, pure white sand, sourced mainly from Wicklow Mountains of Ireland, produces glass of exceptional clarity. In 1676, an Englishman named George Ravenscroft discovered that by adding lead oxide to the pure glass composition, a far more brilliant and sparkling glass could be produced. Lead crystal was born. Besides the highly refractive appearance of lead crystal, this newly discovered glass was also much softer and easier to cut than regular glass.

The maximum lead content in lead crystal is 33%. However, 33% lead crystal requires rare glassblowing skills to shape the crystal into finished products. Consequently, lesser percentage lead crystal is often used, particularly in mass production operations.