Historians claim that the Iron Age began between 1500 and 1000 B.c. (at least in some parts of the world). This does not mean that iron was unknown to man before that time; quite the contrary is the case. Meteoric iron (which has a large nickel content) must have been used by prehistoric people as early as 4000 B.c. They made tools and weapons from it by shaping and hammering. It is thus quite understandable that in some ancient languages the word for iron meant “metal from the sky”. Naturally, the supply of meteoric iron was limited. Thus, stone, copper, and bronze were the materials of choice at least until the second millennium B.c. There were, however, some important uses for iron ores during the Bronze Age and also during the Chalcolithic period. As explained already in Chapter 1, copper needs a fluxing agent for the smelting process when using malachite. For this, iron oxide was utilized, which was known to react during smelting with the unwanted sand particles that are part of malachite. Eventually, a slag was formed which could be easily separated from the copper after the melt had cooled down.