Copper is a dense, rather soft, reddish-coloured metal, with a specific gravity of 8.95 and melting at 1083°C. It is an excellent conductor of both heat and electricity. It is ductile and thus can be easily worked to shape by any of the standard methods described in metal, although it is difficult to cast satisfactorily. It can take and retain a good polish. Apart from gold, it is the only metal that is not white and thus from early times has featured in polychrome decorative schemes with other metals. Its resistance to corrosion and weathering has led to its widespread use for vessels, as well as for protecting buildings from the elements. Copper ores are widely distributed over the Earth’s surface, although copper is sometimes found as a native metal in the upper, oxidized levels of deposits and thus was the first metal to be utilized by man. It continues to find wide application both by itself and as the basis of a wide range of alloys.