I eyeballed/ picked up a rock that looks sorta like an Apollo space capsule from a farm field.It has a paper thin black crust and grey interior where a farmers plow broke it, but my magnet won't stick to it. How do I tell if it is or isn't a meteorite? There is a parking lot there now. There are sparkles inside the rock. I hear there are stony meteorites that are not magnetic? I'll find the rock and post a photo later.   -Tom