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Gold has been used as a symbol for purity, value, royalty, and particularly roles that combine these properties. Gold as a sign of wealth and prestige was ridiculed by Thomas More in his treatise Utopia. On that imaginary island, gold is so abundant that it is used to make chains for slaves, tableware, and lavatory seats.
Often inter-grown, massive, radiated, granular, globular, and stalactitic. The mineral pyrite ( / ˈpaɪraɪt / PY-ryte ), [ 6] or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S 2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. [ 7]
Gold compounds are compounds by the element gold (Au). Although gold is the most noble of the noble metals, [ 1][ 2] it still forms many diverse compounds. The oxidation state of gold in its compounds ranges from −1 to +5, but Au (I) and Au (III) dominate its chemistry. Au (I), referred to as the aurous ion, is the most common oxidation state ...
A nanoparticle or ultrafine particle is a particle of matter 1 to 100 nanometres (nm) in diameter. [ 1][ 2] The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 100 nm in only two directions. [ 2]: 394 At the lowest range, metal particles smaller than 1 nm are usually called atom clusters instead ...
Edible gold is a particular type of gold authorized by the European Union and the United States as a food additive, under the code E 175. It is used in haute cuisine as part of a trend towards extravagance in meals. It can be employed in foods and beverages such as in cookies decoration, wines or liquors; as sushi garnishment; or over ice cream.
Metallic bonding is a type of chemical bonding that arises from the electrostatic attractive force between conduction electrons (in the form of an electron cloud of delocalized electrons) and positively charged metal ions. It may be described as the sharing of free electrons among a structure of positively charged ions ( cations ).
The earliest known Welsh gold mine was the Dolaucothi Gold Mines near Pumsaint in Carmarthenshire, which was initiated by the Romans in or about 74 AD, and closed in 1938 and was donated to the National Trust in 1941. A hoard of gold objects was found near the village of Pumsaint close to the mines in the 18th century and is now in the British ...
Colloidal gold is a sol or colloidal suspension of nanoparticles of gold in a fluid, usually water. [1] The colloid is coloured usually either wine red (for spherical particles less than 100 nm) or blue-purple (for larger spherical particles or nanorods). [2]