This artifact was found outside of Belleville, IL in 1934 while my great grandfather was tilling a garden with a push cultivator outside of his house. Along with the rock were arrow tips and a broken spear with these items. After contacting the Cahokia Museum about these items they replied back saying that they do not believe it is neither Cahokia nor Mississippian in origin. I really have no idea where to go for more information after the museum told me that it was not of their decent. Can anyone help me figure out its origin so I may find the proper place to donate it?