18 September 2010
This was brought in last week by a student… It’s a broken concretion that she found in Des Moines County, Iowa, many years ago. She also had a slab of limestone with crinoid columnal fossils, and a broken geode from the same locality. I think this concretion is a thing of beauty, like a fossilized Gobstopper. I had to photograph it before I gave it back to her.