Why this rock is probably not a meteorite:

No meteorite ever looked like this!
What is it?

This one's a beauty. It's a complex nodular concretion, probably composed of chert. Water with dissolved silica passed through veins in a rock, probably limestone. The silica began to precipitate as cryptocrystalline quartz (chert), possibly on a quartz sand grain. A small nodule formed and grew larger. Other nodules also formed and they eventually grew together. Later, conditions changed and the limestone or other host rock weathered away leaving the more resilient chert.


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.