72. Copper is distinguished from all other metals by its peculiar red color. Its resistance to corrosion when exposed to the atmosphere, combined with its lightness, gives it great value as a roof covering. Copper is very malleable and ductile, and also tenacious; it is found in most countries, the principal mines being those on the shores of Lake Superior, in the United States of America, and at Corocoro, Bolivia, South America.