Search results
Results From The WOW.Com Content Network
The metals of antiquity are the seven metals which humans had identified and found use for in prehistoric times in Africa, Europe and throughout Asia: [1] gold, silver, copper, tin, lead, iron, and mercury. Zinc, arsenic, and antimony were also known during antiquity, but they were not recognised as distinct metals until later.
The early Hittites are known to have bartered iron (meteoric or smelted) for silver, at a rate of 40 times the iron's weight, with Assyria in the first centuries of the second millennium BC. [ 13 ] Meteoric iron was also fashioned into tools in the Arctic when the Thule people of Greenland began making harpoons , knives, ulus and other edged ...
Meteoric iron, sometimes meteoritic iron, [1] is a native metal and early-universe protoplanetary-disk remnant found in meteorites and made from the elements iron and nickel, mainly in the form of the mineral phases kamacite and taenite. Meteoric iron makes up the bulk of iron meteorites but is also found in other meteorites.
Very early copper and bronze working sites in Niger may date to as early as 1500 BC. There is also evidence of iron metallurgy in Termit, Niger from around this period. [ 16 ] [ 74 ] Nubia was a major manufacturer and exporter of iron after the expulsion of the Nubian dynasty from Egypt by the Assyrians in the 7th century BC.
Native metals were prehistoric man's only access to metal, since the process of extracting metals from their ores is thought to have been discovered around 6500 BC. However, native metals could be found only in impractically small amounts, so while copper and iron were known well before the Copper Age and Iron Age , they did not have a large ...
In metallurgy, non-ferrous metals are metals or alloys that do not contain iron (allotropes of iron, ferrite, and so on) in appreciable amounts.. Generally more costly than ferrous metals, non-ferrous metals are used because of desirable properties such as low weight (e.g. aluminium), higher conductivity (e.g. copper), [1] non-magnetic properties or resistance to corrosion (e.g. zinc). [2]
The expression noble metal is sometimes confined to copper, silver, and gold since their full d-subshells can contribute to their noble character. [14] There are also known to be significant contributions from how readily there is overlap of the d-electron states with the orbitals of other elements, particularly for gold. [15]
The find in June 2010 extends the known record of copper smelting by about 800 years, and suggests that copper smelting may have been invented in separate parts of Asia and Europe at that time rather than spreading from a single source. [4] Knowledge of the use of copper was far more widespread than the metal itself.