Think you have a rock from space? Lately, a flurry of people have come to me with a rock or chunk of metal they hope is a meteorite. Whether by the circumstances of the finding or the appearance of the rock or its magnetic properties, the finders thought they might have something.
A couple in Castro Valley even found their specimen next to broken tiles in their backyard--evidence of a meteorite fall? (It turns out their grandson had taken a real meteorite off their mantelpiece and tried breaking it apart against the tiles with impacts of his own....). Another guy wanted to buy a quarter million dollars of insurance on his very unusual "splash" of metal, and won a speeding ticket taking it to the analyst I referred him to...and, alas, it wasn't a meteorite....
None of the rocks brought to me turned out to be meteorites: an oddly shaped scrape of iron, a large (and beautiful) chunk of galena or titanium, a simple Earth stone with an unusual appearance. Don't let this discourage you if you think you have something special. Though meteorite finds are uncommon, they happen, and they can happen anywhere; the sky doesn't discriminate when dropping rocks on us.
Though it's estimated that only three or four meteorites hit the Earth every day, if you do the math you can figure out how many should be lying around from centuries of accumulation (after figuring in that three quarters of them would have fallen into the ocean).
In fact, the largest meteorite ever found in California was stumbled upon by locals: three hunters from Oakland. It was 1938, and they were hunting animals, not space rocks, but one of the men had learned enough about the subject from Chabot Observatory to identify the 2700 pound chunk of nickel-iron as a meteorite.