History

• English glassmaker George Ravenscroft, the first person to add lead oxide to glass in 1676, gets credit for inventing crystal glass.
  
  

Composition

• All glass contains silica, but crystal glass contains the lowest percentage of that mineral at about 33 percent. Crystal's lead oxide content ranges from 33 percent to 58 percent.
  
  

Features

• Lead makes crystal glass soft and easy to cut. The softness can be a challenge to glass makers when they are blowing a crystal glass item.
  
  

Solution

• To counteract the softness and make working with lead crystal easier, glass makers try to keep the lead oxide content to about one-third. This solution results in less-brilliant glassware.
  
  

Considerations

• A good way to tell the difference between regular glass and crystal is by sound. Crystal glass emits a light, reverberating ring, while regular glass gives off a brief, dull thud.