If a rock has a lot of vesicles, then it is not a meteorite

If a rock has a lot of vesicles (gas bubbles, holes), then it is not a meteorite. All of the photos below were sent to me by persons who thought the rocks were meteorites. Many to most of the rocks below are terrestrial volcanic rocks; some are slags. None has a fusion crust because none is a meteorite.

If a rock has many vesicles, then it solidified from a melt or magma, which means, by definition, it is an igneous rock. Few meteorites (some achondrites) are igneous rocks.

Vesicles are not always circular. In some rocks they are elongated because either (1) they were stretched as the molten lava flowed downhill or (2) the lava mostly solidified as the gas bubbles rose to the surface. “Rocks” in which the vesicles have a wide variety of sizes are more likely to be man made (slag); vesicles in natural rocks tend to be more nearly the same size.

More information on vesicles in meteorites. (OK, some meteorites do have vesicles, but not as many as in the rocks pictured here.)

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