Why this rock is probably not a meteorite:

The author found hundreds of thousands of these rocks while walking in a stream bed in southeast Arizona. They can't all be meteorites.
What are they?

They are all terrestrial volcanic rocks that have been rounded by abrasion. The vesicular ones are basalts; most of the rest are ash flow tuffs.  


Prepared by:

Randy L. Korotev

Department of Earth and Planetary Sciences
Washington University in St. Louis

Please don't contact me about the meteorite you think you’ve found until you read this and this.