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Decomposition of organic carbon under anoxic conditions creates a wide range of organic intermediates, e.g., organic acids, that are important determinants of gold mobility. Key microbial processes in the nitrogen cycle can be influenced by gold and vice versa; for example autotrophic denitrifying bacteria can destabilize Au-complexes and may ...
Gold occurs principally as a native metal, i.e., gold itself.Sometimes it is alloyed to a greater or lesser extent with silver, which is called electrum.Native gold can occur as sizeable nuggets, as fine grains or flakes in alluvial deposits, or as grains or microscopic particles (known as colour) embedded in rock minerals.
Such transmutation is possible in particle accelerators or nuclear reactors, although the production cost is estimated to be a trillion times the market price of gold. Since there is only one stable gold isotope, 197 Au, nuclear reactions must create this isotope in order to produce usable gold. [4]
Amalgamation of disrupted continental masses to form new supercontinents, known as Wilson cycles, play a key role in the formation of deposits, by initiating major regional change of the geochemical, mineralogical and structural nature of the lithosphere. [6] Orogenic gold deposits were only formed in certain time slices of the Earth's history.
Most gold is mined as native metal and can be found as nuggets, veins or wires of gold in a rock matrix, or fine grains of gold, mixed in with sediments or bound within rock. The iconic image of gold mining for many is gold panning, which is a method of separating flakes and nuggets of pure gold from river sediments due to their great density ...
Gold's enduring value in modern portfolios is clear, but how you invest in it matters. As we've covered, each gold investment type has pros and cons. So before making any moves, sit down with a ...
Laterite gold deposits are formed from pre-existing gold deposits (including some placer deposits) during prolonged weathering of the bedrock. Gold is deposited within iron oxides in the weathered rock or regolith, and may be further enriched by reworking by erosion. Some laterite deposits are formed by wind erosion of the bedrock leaving a ...
Gold, a chemical element; Genomes OnLine Database; Global-scale Observations of the Limb and Disk, a NASA Explorer Mission of Opportunity; GOLD (parser), an open-source parser-generator of BNF-based grammars; Graduates of the Last Decade, an Institute of Electrical and Electronics Engineers program to garner more university level student members