Why this rock is probably not a meteorite:

1) This is one of several large rocks found in a ravine in Mexico. A ravine full of rocks is among the least likely places to find a meteorite. Meteorites are usually found in places where terrestrial rocks are scarce. Meteorites undoubtedly occur in ravines, it's just that they're hard to recognize among a pile of terrestrial rocks. Also, meteorites don't survive long in wet environments.

2) It doesn't have a fusion crust. It doesn't have the aerodynamic shape of a meteorite.

3) It's got veins or ridges that stick out. If this rock came through the atmosphere from space, the ridges would have been the first things to ablate away.

4) There's a big linear or planar feature running right through the center, top to bottom. Many terrestrial sedimentary rocks have planes because they formed from material settling to the bottom of a sea or ocean. Meteorites don't have linear or planar features because they come from asteroids with no seas and not much gravity.
What is it?

Probably a terrestrial sedimentary rock. Speculation: The sedimentary formation (carbonate?) was fractured and then quartz was deposited from solution in the fractures. The resulting veins are harder and stand out in positive relief because quartz is harder than carbonates.


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.