Q: What are paste diamonds?A: Paste diamonds...

Q: What are paste diamonds?

A: Paste diamonds are basically glass stones that have been chemically modified. The term was introduced in 1662, when the process was discovered. The raw materials include fused silica, soda ash, lead oxide, lime and trace quantities of other chemicals, including boron, phosphorus, barium, zinc and titanium. Paste is usually bright because of its lead content, but it is soft and does not resist wear, as real diamond does. It also is tarnished by sulfur in the air. Rhinestones are glass gems whose brilliance or color is improved by placing metal foils on the bottom facets.