Iron meteorites (which are the ones that respond to magnetism) only make up about 5% of observed meteorite falls. Almost all meteorite falls are of non-magnetic stones and generally look just like stones. Unless they are seen to fall or develop a nice shiny fusion crust during their fall, they are very easy to overlook.
Because they are so distinctive, iron meteorites are found nearly four times as often as stones and maje up almost all of the most massive meteorites which means that iron meteorites are wildly over represented in museum collections.
