Why this rock is probably not a meteorite:

It is a meteorite. I admit that if someone had sent me this photo blind I would have thought it to be an unlikely candidate for a meteorite. The color is OK, but it's angular with minimal fusion crust. The meteor broke apart in the atmosphere and this is but one piece. The meteorite, a shocked L5 chondrite, is a breccia. The light areas are large clasts, the dark areas are matrix of the same material that melted and which contains many fine veins of sulfide. Up close (not visible in this photo) one can see chondrules in the clasts, which would be the most obvious evidence that it was a meteorite.
What is it?

This is one of the Park Forest (Illinois) stones.

See Simon et al. (2004) The fall, recovery, and classification of the Park Forest meteorite. Meteoritics and Planetary Science, vol. 39, no. 4, p. 625-634.


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.