This photo shows the typical Lead Crystal Glass sparkle.
Most people think that crystal glass or lead crystal glass is more expensive, which is right in most case but not in all case. Some fine glassware may contain some lead content but if the 24% lead content level is not reached for a specific item of glassware then a manufacturer cannot by law call that item "crystal” however if the glass has lead in it they can call it “lead glass" or "glass with lead." This law was passed for the main reason that some manufactures would put a little lead in the glass mix and call it crystal just to sell it at a higher price.
What is Lead Crystal Glass?
Lead crystal glass or crystal glass is a variety of glass in which lead replaces the calcium (sand) content of a typical glass mix. Lead glass contains typically 18 to 40--weight percentage of lead oxide in the glass mix while modern day lead crystal glass contains a minimum of 24% lead oxide. The mixture for making glass that includes lead oxide, which produces lead crystal glass, has been used as early as 1400 BC. London glass manufacturer were the first to produce it on an industrial scale in the 17th century. By adding lead oxide to molten glass, the glass crystals create a higher index of refraction. In addition, cutting the surface into intricate patterns further enhances the sparkle in the lead crystal glass.
How do you Spot Lead Crystal glass?
Lead crystal glass is desirable for its decorative properties therefore it is usually on display. There is no exact process to identify lead crystal glass accurately. However, a collector of lead crystal glass needs to understand how to distinguish it from the less valuable glass specimens that are available. Generally, a number of characteristics distinguish lead crystal glass from regular glass.
Hold the glass to the light. If the glass acts as a prism and you can see a rainbow, you are holding crystal. If not, it is just regular glass. (This is number one on the list for the main reason it will help you spot lead crystal glass from a distance, good thing to know, eyes see things first.)
When struck, crystal produces a musical ring. Regular glass does not. (Warning: Lead Crystal Glass is a softer glass than regular glass therefore it will chip easily.)
If you wet your finger and run it around the rim of a lead crystal glass, it will also produce a musical tone. (Only if the glass has a smooth rim and it is thin wall glass, some cut patters need a thicker glass wall for the cut pattern.)
Lead crystal glass can be worked thinner than regular glass, so if the rim of a piece of glass is exceptionally thin it is probably crystal or it is exceptionally thick with a cut pattern it is probably crystal.
If you compare two glasses of the same size, the lead crystal glass will be heavier and will look clearer then regular glass. (regular glass most of the time has a greenish tint to it.)
Lead crystal glass typically has sharp cut edge pattern, while regular glass will have more of a rounded edge pattern. (The best way to learn the different between the two is to compare depression, pressed, or sandwich glass of the 1930’s with lead crystal glass.)
Lead Crystal glass will turn purple if left in the sun for a long time. It is the lead that does this. (Time can take months or year for the glass to turn a deep purple.)
The glassware stored in most people's kitchen cabinets is referred to as the "everyday" glassware. These items have a sturdy, almost indestructible quality that helps them withstand hundreds of dishwashings and plummeting from counter-tops and tabletops. People, often call the glassware reserved for finer use-goblets with etched designs, and pencil-thin stems, crystal. (This type of glass may have lead in it but it does not have the 24% lead content) In most cases, the lead crystal glass is stored in the Dining room China Cabinet. (Do not use this example to help determine wither an item is lead crystal glass or not. Storage location does not mean it is lead crystal glass)