What is this
i post a pic of this rock we had for 20 years.would like to kbow what it was used for and if it worth anything
Greene County Missouri history
Those look like Native American grinding stones. If the round stone and the bowl shaped stone were found together, that is quite a nice set. They used the stones to grind the grains and seeds that they would then cook or bake into their foods. They would use them much like we use a mortar and pestle. Google it to find images that match yours.
Value? Depends on who is buying and how bad they want it.