Crystal is a form of glass combining quartz sand, lead oxide and other minerals. It was first made over 300 years ago.

The most common types, says Swarovski America Limited, are blown crystal, used in vases or stemware, pressed or hand-pressed crystal, found in bowls, goblets or lamp bases, and cut crystal, used to create collectible figurines by grinding and then polishing the surface of the glass.Fine crystal should be chosen for clarity and cut. One guide to quality is the lead oxide content: the more lead, the higher its purity and value, with 30 percent or more lead indicating excellence.