Usually what you see is what you get, but every now and then, a truly valuable piece is tucked behind something innocuous -- or sitting right in front -- on a shelf in a thrift store. That glass ...

The sound of a "ting" from a piece of glass is subjective and it may not actually tell ... Crystal with a lead content over 35 percent will actually sparkle. -Place your thumb into the cut design ...

A woman with long hair holds a glass bowl, examining it to determine whether to purchase it. - Galina Zhigalova/Getty Images ...