I collect meteorites,and have quite a few knocking around my domestic office. Some are astronomical — fist-sized, with one I bring with me when I give talks about impacts so people can hold a piece of an asteroid in their hand — but most are pretty small, and like the size of a finger from the last joint to the tip. A few are pebbles (generally famous ones with special scientific interest,making bigger pieces tough to obtain), and a couple of are sand-grain-sized (one is from the Moon and the other from Mars).
Source: blastr.com