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Gold often occurs in free elemental ( native state ), as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as in electrum ), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite.
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]
White gold is an alloy of gold and at least one white metal (usually nickel, silver, platinum or palladium). [4] Like yellow gold, the purity of white gold is given in karats. White gold's properties vary depending on the metals used and their proportions. A common white gold formulation consists of 90% wt. gold and 10% wt. nickel. [3]
Relativistic quantum chemistry. Relativistic quantum chemistry combines relativistic mechanics with quantum chemistry to calculate elemental properties and structure, especially for the heavier elements of the periodic table. A prominent example is an explanation for the color of gold: due to relativistic effects, it is not silvery like most ...
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 ...
Gold ( 79 Au) has one stable isotope, 197 Au, and 40 radioisotopes, with 195 Au being the most stable with a half-life of 186 days. Gold is currently considered the heaviest monoisotopic element. Bismuth formerly held that distinction until alpha-decay of the 209 Bi isotope was observed. All isotopes of gold are either radioactive or, in the ...
The best known precious metals are the coinage metals, which are gold and silver. Although both have industrial uses, they are better known for their uses in art, jewelry, and coinage. Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely ...
An orogenic gold deposit is a type of hydrothermal mineral deposit. More than 75% of the gold recovered by humans through history belongs to the class of orogenic gold deposits. [ 1] Rock structure is the primary control of orogenic gold mineralization at all scales, as it controls both the transport and deposition processes of the mineralized ...