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Cloth of gold woven with golden strips. Cloth of gold or gold cloth (Latin: Tela aurea) is a fabric woven with a gold-wrapped or spun weft—referred to as "a spirally spun gold strip". In most cases, the core yarn is silk, wrapped (filé) with a band or strip of high content gold.
Non-ferrous metals were the first metals used by humans for metallurgy. Gold, silver and copper existed in their native crystalline yet metallic form. These metals, though rare, could be found in quantities sufficient to attract the attention of humans. Less susceptible to oxygen than most other metals, they can be found even in weathered ...
Dross is a mass of solid impurities floating on a molten metal or dispersed in the metal, such as in wrought iron. It forms on the surface of low- melting-point metals such as tin, lead, zinc or aluminium or alloys by oxidation of the metal. For higher melting point metals and alloys such as steel and silver, oxidized impurities melt and float ...
Puddling (metallurgy) Schematic drawing of a puddling furnace. Puddling is the process of converting pig iron to bar (wrought) iron in a coal fired reverberatory furnace. It was developed in England during the 1780s. The molten pig iron was stirred in a reverberatory furnace, in an oxidizing environment to burn the carbon, resulting in wrought ...
Gold is a chemical element; it has symbol Au ... This improves definition of the position and topography of the specimen surface and increases the spatial resolution ...
The standard gold bar held and traded internationally by central banks and bullion dealers is the Good Delivery bar with a 400 ozt (12.4 kg; 27.4 lb) nominal weight. However, its precise gold content is permitted to vary between 350 ozt (10.9 kg; 24.0 lb) and 430 ozt (13.4 kg; 29.5 lb). The minimum purity required is 99.5% gold.
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 ...
The Iron Age is the final epoch of the three historical Metal Ages, after the Chalcolithic and Bronze Age. [ 1] It has also been considered as the final Age of the three-age division starting with prehistory (before recorded history) and progressing to protohistory (before written history). In this usage, it is preceded by the Stone Age ...