Rust stains on wood decking may be tough to deal with because the iron oxide that stems from the corrosion process can seep deep into the fibers of the wood and require aggressive cleaning methods.

You're looking at an iron-oxide (rust) stain in a granite countertop that could be millions of years old. In my opinion, it's not a defect. (Courtesy of Tim Carter) (Tim Carter) Perspective by Tim ...

The Rainbow Mountains are largely characterized by this iron oxide staining of its sandstone Danxia formation. Most of the time iron oxides impart a dark red pigment , however, there are instances ...