Lead crystal

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Lead crystal beads

Lead crystal, (also called crystal), is lead glass that has been hand or machine cut with facets. Lead oxide added to the molten glass gives lead crystal a much higher index of refraction than normal glass, and consequently much greater "sparkle". The presence of lead also makes the glass softer and easier to cut. Crystal can consist of up to 33% lead, at which point it has the most sparkle. The higher lead content also makes it much more difficult to form crystal during blowing.

Englishman George Ravenscroft discovered crystal in 1676.

Makers of lead crystal objects include Baccarat in France, Royal Leerdam Crystal of the Netherlands, Steuben Glass in the United States, Waterford Crystal in Ireland, Mikasa in Japan, and Swarovski in Austria.

[edit] Lead crystal and food safety

Significant amounts of lead can migrate from lead crystal containers into beverages stored in them.^[1] Lead crystal typically contains 24–32 percent lead oxide. In a study performed at North Carolina State University, the amount of lead migration was measured for port wine stored in lead crystal decanters. After two days, lead levels were 89 µg/L (micrograms per liter). After four months, lead levels were between 2,000 and 5,000 µg/L. White wine doubled its lead content within an hour of storage and tripled it within four hours. Some brandy stored in lead crystal for over five years had lead levels around 20,000 µg/L.^{[citation needed]} To put this into perspective, EPA's lead standard for drinking water is 15 µg/L = 15ppb.^[2] Citrus juices and infant formula leach lead from crystal just as effectively as alcoholic beverages. Several companies do make lead crystal baby bottles and it is suspected they may present a health danger to infants.^{[citation needed]}

[edit] References

^ Angela M. Fraser, Ph.D., Associate Professor/Food Safety Specialist, and Carolyn J. Lackey, Ph.D., R.D., L.D.N., Professor/Food and Nutrition Specialist, North Carolina State University (2004)
^ Commonly Asked Questions: Section 1417 of the Safe Drinking Water Act and the NSF Standard