Iron metal is not easily ground or crushed.
Iron(II) sulfate pentahydrate,FeSO4·5H2O, eventually swings toward a magnet.
A sample of potassium hexacyanoferrate(II),K4Fe(CN)6, is shown to be diamagnetic.
Powdered iron and powdered iodine are mixed together. Adding drops of water to the mixture initiates a reaction.