The characteristic red color of red clay is primarily due to the presence of iron oxide.
Red clay is a mixture of several natural minerals, including clay minerals. The iron oxide (specifically, forms like hematite - Fe2O3 - and goethite - FeO(OH)), gives the clay its reddish hue. Other minerals present in red clay include quartz, feldspars, oxidized titanium, and other earthy oxides. The precise mineral composition can vary depending on the geological origin of the clay. However, the iron oxide is the key component responsible for its distinctive color.
