This is a very simple, and practical primitive tool made by hafting (setting-in or lashing-in) a stone flake to a handle. This is a 2,700 year old design found near western Washington's Hoko River.
Sharp stone flakes are quite useful naked, but adding a handle can increase, leverage, dexterity, and over-all usability. Just take a stone flake, and place it between a split twig or small stick, lash it into place using whatever cordage is available.
WARNING: Stone flakes are extremely sharp and dangerous, so severe injury can result in mishandling or misuse.