Metals of antiquity Metals of antiquity The metals of antiquity are the seven metals which humans had identified and found use for in prehistoric times: gold, silver, copper, tin, lead, iron, and mercury. These seven are the metals from which the modern world was forged; until the discovery of arsenic in the 13th century, these were the only known elemental metals, compared to the 86 known today. The metals of antiquity generally have low melting points, with iron being the exception. While all the metals of antiquity but tin and lead occur natively, only gold and silver are commonly found as the native
Permanente Metals short tons of goop-filled bombs were used in World War II (approximately eight percent of the total tonnage of incendiaries that were dropped during that conflict). Permanente ranked 42nd among United States corporations in the value of World War II military production contracts. Permanente Metals Permanente Metals Corporation (PMC) is best known for having managed the Richmond Shipyards in Richmond, California, owned by one of industrialist Henry J. Kaiser's many corporations, and also engaged in related corporate activities. These four of the seven west coast Kaiser Shipyards were known for their construction of Liberty ships. The company was also a