Oxidation

Weathering by oxidation is common in rocks which are rich in the elements that can be easily oxidised e.g. iron.  Iron as Fe²⁺present in a mineral is oxidised to Fe³⁺state. This change in the oxidation state causes an adjustment leading to a less stable mineral which is subject to both disintegration and decomposition.  In other words, when ions such as Fe²⁺ are removed or are oxidised within the minerals, the rigidity of the mineral structure is weakened and the mechanical breakdown is made easier. This provides a favourable environment for further chemical reactions. Increased temperatures and the presence of precipitation will accelerate the oxidation process.