GOLD, an extremely heavy, very valuable, bright yellow metal, with a resplendent lustre (symbol Au, atomic number 79, atomic weight 197.2). On account of its brilliant appearance, unalterability and occurrence in the native condition, gold was almost certainly the first metal to attract the attention of man. It was known and highly valued by the earliest civilizations, Egyptian, Minoan, Assyrian and Etruscan, and from all these periods ornaments of great variety and beautiful and elaborate workmanship have survived, many of them being as perfect now as when they were first made several thousands of years ago. (See