III.

Characteristics of Metalwork

All metals share certain characteristics: a uniform smooth complexion; great strength and tenacity, but also easily worked surfaces; and malleability (their capacity to assume any desired shape). This inherent malleability of metals is exploited by pressure in its solid state or by molding when it is liquefied by heat. In addition, metals were the first reusable materials known (unlike stone, shell, or wood), since broken or obsolete metal objects can be melted down and the substance reused. This relative permanence came to be appreciated after the discovery of smelting in about the middle of the 5th millennium bc.