The William M Thomas Planetarium is sometimes called upon to determine whether or not a strange rock is a meteorite. A rock with thin black fusion crust and/or is magnetic is a possible candidate but usually it is a terrestrial rock. Here is what the Planetarium Director, Nick Strobel, does when presented with a strange rock:
He sees if one of our Geology faculty can identify the rock as a terrestrial rock (select the link and search for "Geology" in the faculty job titles).
He checks out the following websites about meteorite identification: