The brilliance of lead crystal relies on the high refractive index caused by the lead content. Ordinary glass has a refractive index of n = 1.5, while the addition of lead produces a range up to 1.7 or 1.8. This heightened refractive index also correlates with increased dispersion, which measures the degree to which a medium separates light into its component spectra, as in a prism. Crystal cutting techniques exploit these properties to create a brilliant, sparkling effect as each cut facet reflects and transmits light through the object. The high refractive index is useful for lens making, since a given focal length can be achieved with a thinner lens. However, the dispersion must be corrected by other components of the lens system if it is to be achromatic.
The addition of lead oxide to potash glass also reduces its viscosity, rendering it more fluid than ordinary soda glass above softening temperature (about 600 °C or 1,112 °F), with a working point of 800 °C (1,470 °F). The viscosity of glass varies radically with temperature, but that of lead glass is roughly 100 times less than that of ordinary soda glasses across working temperature ranges (up to 1,100 °C or 2,010 °F). From the glassmaker’s perspective, this results in two practical developments. First, lead glass may be worked at a lower temperature, leading to its use in enamelling, and second, clear vessels may be made free from trapped air bubbles with considerably less difficulty than with ordinary glasses, allowing the manufacture of perfectly clear, flawless objects. When tapped, lead crystal makes a ringing sound, unlike ordinary glasses. Consumers still rely on this property to distinguish it from cheaper glasses. Since the potassium ions are bound more tightly in a lead-silica matrix than in a soda-lime glass, the former when struck absorbs more energy. This causes the lead crystal to oscillate, thereby producing its characteristic sound. Lead also increases the solubility of tin, copper, and antimony, leading to its use in colored enamels and glazes. The low viscosity of lead glass melt is the reason for typically high lead oxide content in the glass solders.
The presence of lead is used in glasses absorbing gamma radiation and X-rays, used in radiation shielding (e.g. in cathode ray tubes, where lowering the exposure of the viewer to soft X-rays is of concern).
The high ionic radius of the Pb2+ ion renders it highly immobile in the matrix and hinders the movement of other ions; lead glasses therefore have high electrical resistance, about two orders of magnitude higher than soda-lime glass (108.5 vs 106.5 Ohm·cm, DC at 250 °C or 482 °F). Lead-containing glass is therefore frequently used in light fixtures.
Lead Crystal Awards
Creative Crystal Awards the leading manufacturer and supplier of Lead Crystal Awards and Lead Crystal Trophies. You will be amazed by our custom hand polished Crystal products and Crystal Awards. In our online shopping store you will find some unique collections of lead crystal vase, lead crystal bowls, lead crystal glassware and lead crystal trophies suitable for employee recognition awards, personalized awards, corporate awards, sports awards. Our skilled crystal designer can produce any types of hand cut crystal products as needs. Contact with us and get our exclusive 2016 Crystal Awards Catalogs.
Creative Crystal Awards is the leading Crystal Awards manufacturer in USA. Over 15 years we are supplying fine quality Engraved Crystal Awards, Crystal Trophies, Engraved glass awards, Glass Trophies, Art Glass Products and Corporate Gifts for small business organizations to Fortune 500 companies and shipping around the word. Now, we are the America’s leading Crystal Awards manufacturer and supplier, producing high quality crystal awards, fast turn around time and 100% customer satisfaction guaranteed.
Whether you are looking for Custom Crystal Awards or Corporate Crystal Trophies, our brilliant and professional corporate award designers will produce quality awards in our own glass factory. In our online corporate awards shopping store you will find huge range of stunning unique crystal awards, custom crystal awards, lead crystal awards, crystal corporate awards, crystal sports awards, crystal acrylic awards, crystal recognition awards, Glassware, Art glass Products, Hard-grave Crystal Award, Glass Trophy and promotional gifts which are suitable for your corporate award events, employee recognition awards and corporate promotional gifts. CreativeCrystalAwards.com top supplier of corporate awards at very low price and offering FREE Setup, FREE Engraving and FREE Shipping for your award events.
We have 2000+ fine Awards, Trophies and Gifts in our product line. You can simply request for our latest FREE Awards Catalog or you can contact with one of our specialists for any of your custom awards inquiry.