Groundstone Tools vs Natural Stones

Have you ever found an interesting rock and wondered whether it was natural, or something people shaped in the past? Here Dr. Connie Arzigian talks about some ways to tell the difference. Check the timestamps below to find information on different types of artifacts and similar-looking natural rocks, and what archaeologists look for to determine whether a stone is natural or worked.

Dr. Connie Arzigian is an MVAC Senior Research Associate and Senior Lecturer, University of Wisconsin–La Crosse, Department of Archaeology & Anthropology

Here’s what the video covers, and some links for further information:

00:06 – Introduction
01:10 – Axes and Celts
04:53 – Stones with Grooves
08:35 – Shaped and Pecked Stone: Manos, Hammerstones
11:49 – Shaped and Pecked Stone: Manos and Metates
12:48 – Deliberately Etched Stones, Abraders, and Natural Stone
15:16 – Natural Iron Concretion Used as a Paint Pot (for further information on natural iron concretions:
16:07 – Frost Fracture
16:40 – Human-Drilled Holes Versus Natural Holes (Omar Stones, Fossils) (for further information on omar stones:
20:41 – The Importance of Context
21:43 – What Do I Do If It’s an Artifact? (for further information:
23:08 – Credits

Artifact Identification
Mississippi Valley Archaeology Center at the University of Wisconsin–La Crosse works mainly in Wisconsin, Minnesota, and Iowa and can provide information related to that region. If you would like information on artifacts, email a description of the item and where it was found, and attach a picture of the artifact with a scale to show its size. For more information visit MVAC’s website at:

For information on other regions, we suggest contacting the appropriate state archaeologist from the following list: