I got this back in the early 70's from the ranch that I grew being allowed to hunt as well as hunt for artifacts. I did not find this artifact, but it was being used to hold the back door (also the kitchen door) of the ranch house. So the white marks came from the kitchen wall and the white wooden door. It was being used as a door stop!! Never wanted to clean the paint scuffs up.. The rock weighs over 5 1/2 pounds alone. Anyway, she gave it to me and I've had it since.
On this property, I found a ceremonial pipe that the Museum in Canyon Texas stated it was from the Missouri Valley.. Just a very special area in the Texas Panhandle.