RichPA said:Nice points and thanks for sharing finds from SWPA. Not sure on the black material but Upper Mercer, Kanawha, and Ten Mile are black materials found in the area from site reports.
The gray material is probably Monongahela chert. It is described as being blue, from dark blue to light blue/gray and in some instances passing into chalcedony. It patinates to lighter shades.
Is the rootbeer colored chalcedony flint ridge?