Copper is often overlooked as a precious metal because of its more popular use as an industrial metal. While gold and silver are used largely within the jewelry and precious metal (coin, bar, and round) markets today, copper is used both in the production of bullion bars and commemorative rounds. As an industrial metal, copper has played a huge role in human history. It was first used as far back as 9,000 BC to create armor, jewelry, and even everyday plates and utensils. It was also used as an alloy to create new materials such as brass and bronze. Today, it is commonly used in construction for piping and electrical wiring due to its electrical and thermal conductivity and resistance to corrosion. The other popular design currently available features the copper listing from the periodic table of elements. Included in the design is the square from the table, which includes the Cu listing for copper, as well as its number in the table. Additional engravings include the bars weight, metal content, purity, and origin as U.S.A.