Question

What effect does oxidation have on the colour of rocks?

Answer 1

Oxidation can change the colour of rocks. When rocks containing iron minerals undergo oxidation, the iron reacts with oxygen to form iron oxide (rust), which gives the rock a reddish-brown or yellowish-brown colour. This is why many rocks that undergo oxidation, such as those containing haematite or magnetite, often change from their original colour to shades of red or brown.