Why this rock is probably not a meteorite:

Maybe it is. It (top photo) resembles a pallasite, if the grayish matrix is metal, which one can't tell for certain from the photo. Olivine grains in a pallasite are usually more euhedral* than this. Also, if this were a pallasite, it could only have been cut with a saw. It's not evident that there are any saw marks and the face is not obviously flat.

*euhedral: crystals completely bounded by plane faces

What is it?

If it's not a pallasite, we don't know what it is. 

Note added later

The top photo was sent to us by the finder. The bottom photo I took myself after the owner sent the rock to me. This is a wonderful example of why I CAN'T IDENTIFY A METEORITE FROM A PHOTOGRAPH. In the bottom photo, the clasts are clearly not olivine and the matrix is clearly not metal - the rock is not a pallasite.

The matrix of the rock fizzes (gives off gas bubbles) when a drop of hydrochloric acid is placed on it. This means that it is composed of carbonate. It also means that it is not any kind of meteorite. It's some kind of terrestrial conglomerate.  There are carbonaceous meteorites, but no carbonate meteorites. 


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.