Lead glass
From Wikipedia, the free encyclopedia
Lead glass is potassium silicate glass which has been impregnated with lead oxide (from 12% to 28% by weight) in its fabrication. The lead is not intended to reduce the glass's ability to transmit light; depending on what the end use is to be, the goal is either to allow the glass to transmit visible light but to block x-rays, or to increase the refractive index of the glass, and thus its lustre, or sparkle. Its ability to refract light more efficiently than standard glass makes it an excellent material for prisms, decorative windows, and artificial jewelry.
Lead glass's primary contemporary use is in the construction of televisions and monitors. In a standard cathode ray tube, high-energy electrons are fired at phosphors painted on the inside of the tube. This impact creates the visible light the monitor or TV screen produces; it also produces X-rays. The lead in the glass acts as a barrier to this unwanted radiation. Unfortunately, the amount of lead glass finding its way into landfills as a result of discarded electronic equipment may be more of a hazard than the radiation it is designed to block.[citation needed] Lead glass has been used in aircraft used in testing nuclear weapons for this radiation blocking effect.
Cut lead glass, also known as lead crystal, is used in fine tableware, particularly wine glasses and decanters. It was unknown until a few decades ago that alcohol stored in a decanter was capable of leaching the lead, which is toxic, from the glass and contaminating the contents.[1] While fine wine glasses are still made of lead glass, use of lead glass containers for storage longer than same-day serving of any sort of alcoholic beverages is discouraged. In addition, lead(II) acetate has a slightly sweet taste, which may lead people to believe that wine from a leaded container has an enhanced flavor.
