You didn't find a meteorite
by Cory Doctorow from on (#1RC5Z)
Randy L. Korotev from the Washington U in St Louis Department of Earth and Planetary Sciences presents this handy flowchart (based on this one by Deborah Guedes) for deflating your excitement at having found rock that may be a meteorite but almost certainly isn't. Today's XKCD offers a handy abridgment if you find this one excessive.