Metals
A metal is an elementary substance, such as gold, silver or copper, that is crystalline when solid. Metals are characteristically opaque, ductile, conductive, and lustrous when freshly fractured[1].
In Chemistry, a metal is any such a substance in its pure state, and unalloyed. Metals are elements that yield positively charged ions in aqueous solutions of its salts.
See also base metal, precious metals and rare earth metals.
Precious metals, including gold, silver, platinum and palladium are traded in OTC markets, as well as futures markets around the world, including the CME Group, NYSE Liffe U.S., TOCOM, and others.
Base metals, such as copper, lead, aluminum, nickel and others, also trade in OTC and futures markets, although the trade is concentrated at the London Metal Exchange.