Why this rock is probably not a meteorite:

When I saw this photo, I said "That's an iron meteorite!" It does have a morphology like some iron meteorites. [Do a Google search on "Sikhote-Alin", "Henbury meteorite", or "Campo del Cielo meteorite" for dealer photos. Here's one that I took of small fragments of Sikhote-Alin.] If I'd been more careful before blurting, it would have occurred to me that the bottom of this thing must be rather flat for it to be sitting so close to the table in the photo. There are no extensive flat parts on a meteorite.
What is it?

We analyzed a small piece of this thing. It's iron metal with impurities. The nickel concentration was <0.3%. In an iron meteorite it's greater than 5%. Iridium was <1 ppb. Any iron meteorite would have >5 ppb and most would have several hundred or more.

It was found in western Colorado. It's probably waste from an old smelter or forge. I suspect that molten metal was poured on the ground, apparently on gravel or rocks. The original top of the molten metal (now, the bottom in the photo) was above the rocks, so the top solidified flat. The original bottom, the surface we see in the photo, is a cast of the rocky surface.


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.