What are the precious metals?
Precious metals is a general term that describes expensive metals used for making coins, jewelry, and ornaments. Precious metals include gold, silver, and platinum. Precious metals are defined by two criteria: one is that they are scarce in the Earth’s crust (compared to other metals); and the other is that they are noble. A noble metal is one that has a high resistance to chemical change. “Precious metals” is not synonymous with “noble metals.” While it is true that all precious metals are noble metals, the reverse is not true. Sources: Brady, George S. Materials Handbook, 13th ed., pp. 663-64; “Extraction and Processing Industries: Precious Metals.” Encyclopaedia Britannica CD 97; Savitskii, E.M. Handbook of Precious Metals, pp. xv-xIx.
