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The metallicity of an astronomical object is the proportion of its matter made up of the heavier chemical elements. [ 6 ] [ 7 ] The strength and resilience of some metals has led to their frequent use in, for example, high-rise building and bridge construction , as well as most vehicles, many home appliances , tools, pipes, and railroad tracks.
South American metal working seems to have developed in the Andean region of modern Peru, Bolivia, Ecuador, Chile, and Argentina with gold and native copper being hammered and shaped into intricate objects, particularly ornaments. [1] [5] Recent finds date the earliest gold work to 2155–1936 BC. [1] and the earliest copper work to 1432–1132 BC.
Derveni krater, bronze, 350 BC, height: 90.5 cm (35 1 ⁄ 2 in.), Inv. B1, Archaeological Museum of Thessaloniki, after cleaning and conservation. Conservation and restoration of metals is the activity devoted to the protection and preservation of historical (religious, artistic, technical and ethnographic) and archaeological objects made partly or entirely of metal.
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Metalworking is the process of shaping and reshaping metals in order to create useful objects, parts, assemblies, and large scale structures. As a term, it covers a wide and diverse range of processes, skills, and tools for producing objects on every scale: from huge ships, buildings, and bridges, down to precise engine parts and delicate jewelry.
Alloys are made by mixing two or more elements, at least one of which is a metal. This is usually called the primary metal or the base metal, and the name of this metal may also be the name of the alloy. The other constituents may or may not be metals but, when mixed with the molten base, they will be soluble and dissolve into the mixture. The ...
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The oldest known iron objects used by humans are some beads of meteoric iron, made in Egypt in about 4000 BC. The discovery of smelting around 3000 BC led to the start of the Iron Age around 1200 BC [ 16 ] and the prominent use of iron for tools and weapons. [ 17 ]