At root, crystal is comprised of silica (sand), potash (a manufactured salt derived from potassium) and lead oxide. Lead oxide is added to a basic glass mixture for its optical refraction effects. Traditionally, lead content has been the defining feature of crystal.Leaded glass is typically used in church windows and for certain applications in older homes and typically contains 5-20% lead, usually on the lower side, as increasing lead content also increases the brittleness and the fragility of the glass.
These days, leaded glass isn't generally used in contemporary window-treatments, but the same basic formula is used in cheaper chandelier crystal. Traditionally, once the lead content gets above 20%, it is considered to be "crystal" - though these days the term crystal is loosely applied to all chandelier glass adornments regardless of lead content. The optimal lead content for crystal is between 20 and 30%, which allows for greatest refraction of light. It should also be noted that lead oxide is no longer the only additive which can produce refraction. Because of restrictions on lead content in the last twenty years by both California and The European Union, a number of crystal manufacturers have introduced "lead-free" crystal, which contain different additives, such as barium, zinc, or potassium oxides, which also increase the refractive properties of glass.
While higher lead content tends to make crystal more fragile, this is less of a problem for chandelier crystals than it is for other types of crystal (decanters, stemware, etc.), which need to be more robust because they are regularly handled. Once the chandelier crystal is in place, fragility shouldn’t be much of a problem, assuming that you’re not regularly swatting insects or bats anywhere near your chandelier. Or swinging from it, as the Sia song goes. But lead content is only one of the factors that indicate crystal quality. The care taken during the manufacturing process of crystal is perhaps even more important in determining quality than the raw ingredients.
If you are looking for more details, kindly visit china crystal chandelier accessorises manufacturers.
The company is the world’s best custom hotel lobby chandelier supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.
For more customizedized large hotel lobby lightinginformation, please contact us. We will provide professional answers.