Found this rock with layers has what appears to be gray or brown dirt in the center Found in the Tx hill country
what is it and how can I find out its age ? Was one solid rock.
An ironstone nodule, split in half to show the layers of different forms of iron oxide minerals, mostly limonite and goethite. I've been to Marble Falls Texas, I was selling rock drill bits to a dimensional stone quarry. I'm thinking the quarry was owned by Cold Springs Granite out of Minnesota. It was a long time ago. I remember I liked the country down there.