Why this rock is probably not a meteorite:
No fusion crust; exterior too rough.
What is it?

Someone found this rock in a mineral collection that he purchased from a geologist and sent it to us to examine. It didn't have a label.

This rock is almost certainly a fulgurite - a rock form by lightning striking the ground. It's cylindrical, with a glassy center and exterior composed of fused rock and soil. The top photo shows a side view; the two bottom photos show the broken ends, looking down the cylindrical axis. Glassy areas (dark green) occur in all views.  


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.