Editing Weathering (section)

===Oxidation===
[[File:GoldinPyriteDrainage acide.JPG|thumb|A [[pyrite]] cube has dissolved away from host rock, leaving [[gold]] particles behind.]]
[[File:PyOx.JPG|thumb|Oxidized [[pyrite]] cubes]]
Within the weathering environment, chemical [[oxidation]] of a variety of metals occurs. The most commonly observed is the oxidation of Fe<sup>2+</sup> ([[iron]]) by oxygen and water to form Fe<sup>3+</sup> oxides and hydroxides such as [[goethite]], [[limonite]], and [[hematite]]. This gives the affected rocks a reddish-brown coloration on the surface which crumbles easily and weakens the rock. Many other metallic ores and minerals oxidize and hydrate to produce colored deposits, as does sulfur during the weathering of [[sulfide mineral]]s such as [[chalcopyrite]]s or CuFeS<sub>2</sub> oxidizing to [[copper hydroxide]] and [[iron oxide]]s.{{sfn|Boggs|2006|p=9}}