Page 37 - Curriculum Visions Dynamic Book

(Above) The first exploitation of metal probably came about as
a result of accidentally using an ore as a hearth rock in cooking. Part of the rock got soft so that it could be worked, or it may have dripped from the rock as pure metal.
Because these metals are
soft, they are easily worked by hammering with stone tools. They will also melt, or at least soften, at the low temperatures of open fires.
Gold is the easiest of the native metals to work because
a large sheet can be formed simply by hammering together small nuggets. The gold does not need to be heated or treated in any way. Gold is also attractive. As a result, one of its first uses
was for jewellery (although it was also made into armor breastplates as protection in battle).
To get small pieces of other native metals such as copper or silver to mix together, they must be heated until they melt. The accidental discovery of how solid metals turn into liquids and run together was probably made in an open hearth used for cooking. If the rocks used for the hearth were rich in copper or silver, the metals could easily have been seen as they flowed out.
The Bronze Age
Although the earliest known examples of melting copper to make axe heads can be dated back 6,000 years, the time in history when metal became an important material was the Bronze Age.
The Bronze Age began in different places at different times. In Asia and Europe it began between 5,000 and 4,000 years ago. It was perhaps as accidental in its beginnings as the finding and working of gold.
Bronze is a mixture (alloy) of copper and tin. Some rocks naturally contain both metals. Stannite, for example, is an ore that contains a mixture of copper, iron, and
tin, and so the substance that was produced when it was heated was bronze.
Bronze was probably first discovered in the Middle East. Bronze is harder than copper or tin. It also has
a lower melting point than tin and is easily poured
(Above) Native copper.
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