Steelmaking

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The earliest recorded metal employed by humans appears to be gold which can be found free or "native". Small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c. 40,000 BC. It is clear that some of the aspects of metallurgy were present even in early biblical times. From Exodus when know that the Israelites melted down their golden objects and created the golden calf as an idol. There are many other references to gold scattered in the bible, such as the gold used to build the ark of the covenant. However, this gold seems to have been only used for decoration, idols or other "works of art", and never used for tools, weapons and other such things.

There are two reasons behind why this is probably the case. For one, gold was still valuable and rare, no one would think of using a golden pitchfork. Also gold is a very soft metal, and thus cannot be used for hard tasks as it will bend and break easily. The reason gold was common before any other metals is also rather simply, things like silver, copper and iron are all found in veins, while gold is more common in lump form. Thus gold was much easier to extract without proper tools. All of these are the main reasons why gold was used commonly before copper or iron-yet wasn't ever a vital part of its time periods way of life.

The first metal which was largely used in trade, exploration, welfare and other aspects of life was copper. The reddish-brown metal that is found in a penny was more common in the Middle Eastern area than gold while it melted as the same temperature. However it was harder to extract from a rock face, and people probably did not see how useful it was right away. Copper is also sturdier than gold and thus had more uses. The identified first use of copper was around 4000 BC. It started appearing more regularly as trade expanded. Many areas had the copper ore but could not melt it down because they did not have enough energy to build a fire hot enough to melt the copper. Other places had this energy, but had no ore. « mai multe referate din Diverse