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23 Απρ 2023 · Primary silver minerals in rocks can be weathered and broken down, releasing silver into groundwater or surface water. The dissolved silver can then be transported and deposited in other locations, forming secondary enrichment zones where silver accumulates in higher concentrations.
Native silver is sometimes found in the oxidized zones above the ores of other metals. It persists there because silver does not readily react with oxygen or water. It does react with hydrogen sulfide to produce a tarnished surface that is composed of the silver sulfide mineral known as acanthite.
5 ημέρες πριν · A rock containing silver will have a dark, almost sooty appearance or dark crystals within the rock. There are several different types of silver ore in the world depending on the geography. Some have gray spider-like veins running through the rocks, while others can be more gray or black in color.
Silver tarnishes black with a surface layer of acanthite (silver sulphide), especially when placed in proximity to sulphurous compounds. It is primarily found as a constituent of hydrothermal veins. It is often found associated with copper. Unlike gold, it is soluble in any oxidizing mineral acid.
Silver occurs as pyrargyrite, cerargyrite, acanthite and native Ag, in all cases finely disseminated throughout the host rocks. Associated ore minerals are sphalerite, stibnite, chalcopyrite and galena; the gangue is quartz, calcite, sericite, barite and/or fluorite.
23 Απρ 2023 · Most silver is produced as a byproduct of copper, gold, lead, and zinc refining. It has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes alongside gold: while it is more abundant than gold, it is much less abundant as a native metal.
31 Οκτ 2024 · argentite Argentite from Freiberg, Germany. Silver ornaments and decorations have been found in royal tombs dating back as far as 4000 bce. It is probable that both gold and silver were used as money by 800 bce in all countries between the Indus and the Nile.
