Metal Crafts Metallurgy began in Bengal as early as 1500 BC in the Chalcolithic Age. The full-fledged use of iron is noticed in about 1000 BC. Copper and its alloy and iron were the most used metals, although silver and gold were also used on a limited scale. Today, artists use this ancient art form to convey new generation visions and artforms. Bells, which signify spirituality, new beginnings and deep religious sentiments all over the world have been one of the oldest expressions of art in metal.