Herb’s Rustoration is a safe and effective rust remover for all natural and engineered stone. The pH neutral formula is acid-free and enviromentally friendly. Marble, granite solid surfaces and engineered stone can be treated with Herb’s Rustoration Rust Remover. When the cleaner is applied to rust covered stone, the formula chemically bonds with the iron in the rust and turns it red, making it water-soluble and easy to agitate and rinse away. The product can be used on any surface with rust present including the exterior of homes and plumbing fixtures.