The reason crystal is called crystal is because it has lead crystal mixed with silicon.
I am not quite sure as to why or how the lead becomes transparent. Anyone know the physics behind why lead, a metal can become transparent? And can all metals become transparent when mixed with silicon?
But the question on my mind is the health question of how many atoms of lead does one ingest when drinking from a crystal glass containing lead. I suppose most people would say zero number of lead atoms gets into the body. I however am skeptical of that claim and would hazard to guess that a few atoms of lead are taken into the body whenever a person drinks wine from a crystal glass.
Archimedes Plutonium
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whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies
Its glass, crystal is just a cultural echo and a way of putting up the price.
Glass can contain all sorts of metal oxides and still be transparent.
How much lead is a safe dose? It tends to hang around in bones anyway but the quantities from a glass of wine are pretty low and the effects of the alcohol probably outweigh this.
What is the most damaging rate to drink wine from a high lead wine glass? Drink too fast and not much lead dissolves, too slow and your main course will be cold and the waiter will be looking at the clock and giving big hints to leave.
Drinking from not very well fired coffee cups with a glaze containing lead on the other hand might have been a problem in the past.
Actually lead carbonate is white and is used as a pigment in paints and pottery years ago. Lead has several stable valence states in which PbO is yellow to orange powder, Pb3O4 is a red powder, and PbO2 is a black powder.
In terms of the leaded crystal glass, the lead is in solid solution with the silicon dioxide and other glass additives including boron and sodium. The heavy lead elements decreases the speed of light through the crystal, thus increasing the refractive index giving crystal a certain brilliance. Under certain conditions lead can be leached out the glass and into particularly hot and/or acidic foods or liquids. The national safety council states that lead can be a hazard in both leaded crystal and ceramic glazes as stated below:
Ordinary glassware does not contain lead, but lead is used to make the more expensive lead crystal. People who have lead crystal items should take the following precautions:
Do not store liquids in lead crystal glasses or bottles. Do not drink from lead crystal on a daily basis, especially if you are pregnant. Do not feed an infant or child from a lead crystal baby bottle or cup.
Since 1980, FDA has had limits on lead and cadmium in ceramic ware products. The limits were lowered in 1991 to reduce consumer exposure to lead in food from ceramic dishes that may have lead glazes. Most ceramic ware items sold in the United States meet current FDA limits because manufactures tightly control the way they make dishes to minimize the potential for lead to leach into food.
To avoid possible exposure to lead from ceramics and other tableware, consumers should take the following precautions:
Do not store food in any dishes that may contain lead. Do not store food in antiques or collectibles Be wary of using or of storing food or beverages in highly decorated or metallic-coated tableware, particularly items made in other countries or by amateurs and hobbyists. Pregnant women should limit their use of lead-glazed mugs or cups for hot beverages, since lead is harmful to fetuses
Most manufacturers of fine crystal have their own special blend of lead-free crystal to eliminate concerns of lead exposure. These usually contain medleys of additives like zirconium, tungsten, hafnium, antimony, and the rare earth lanthanides to yield the high index of leaded crystal.
Dont go throwing away your crystal, this leaded crystal may be a hazard from the national safety committes, but I have never heard of anyone getting lead poisoning from crystal glass just yet.
In article , snipped-for-privacy@yahoo.com (Ceraboy) wrote: (snip)
(snip)
1) Get over it. As others have said, the amount of lead here is tiny compared to other sources. :)
2) Stop worrying about tiny risks. Have more fun. Laugh a bit :)
Bruce
------------------------------ Health nuts are going to feel stupid someday, lying in hospitals dying of nothing.
-Redd Foxx
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Be aware that pottery from some Latin American countries may still use lead containing glazes. These can in fact give you a significant lead exposure over time. I know because my daughter brought some back from Peru last year!
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