lead crystal
Lead crystal is made from glass that has been treated with lead oxide and hand or machine cut to make facets. Lead crystal, also called crystal.nglishman George Ravenscroft is credited with discovering lead crystal in 1676. Today, popular manufacturers of lead crystal include Waterford Crystal, Swarovski, Steuban Glass, Royal Leerdam, Mikasa, and Baccarat. Lead oxide added to the molten glass gives lead crystal a much higher index of refraction than normal glass, and consequently much greater "sparkle" by increasing specular reflection and the range of angles of total internal reflection.
Over time a film forms on the surface that makes the glass look slightly milky. The problem is that may be you haven’t yet found a good way to really clean it.Full lead crystal is "softer" than regular glass, and it will scratch, so it should be stored where it will not touch your other pieces of crystal or any dishes for that matter. Do not store glasses upside down-this may cause stress to the rim.Dust can act as an abrasive and can "scratch" the surface. Make sure you only clean with a mild detergent and use a lint free cloth for drying.For glasses with gold rims or an edge design, never soak in solutions containing ammonia. Stick to using a mild detergent only.