This is a vase grinder.
It is from Memphis. Stone workerrs used vase grinders in different shapes and sizes to bore out the inside of stone jars. They started by shaping the outside of the jar, and drilled out a central core using a hollow drill bit of copper. They then used shaped grinders, held in a forked stick, to hollow out the jar. This is a vase grinder. It is made from quartzite stone. We do not know how old this object is.