Really? I got some pretty big rare earth magnets I scavenged from a SCSI hard drive. Those things can smash your fingers if you aren't careful! The only compounds I really know that involve iron is well.. iron, and iron oxide. Steel has iron and a bunch of other goodies in it, and thats kinda magnetic too. So maybe ferrous properties DO follow the iron around, but are mitigated by other stuff thats stuck to it. I imagine the oxide portion of iron oxide doesn't want its electron spin messed with unlike iron.