Many rust removers are acidic, and their labels warn that they might etch tile, so try an alkaline rust remover, such as ConfiAd Rust Remover Gel ($37.95 at mystonecare.com).

The Rust collection is available in a curated palette of 12 colours, incorporating earthy browns, olive greens and soft blues and greys. The tiles can be mixed-and-matched with other Modulyss designs.