A preform is the rough, incomplete and unused basic form of a stone tool formed by lithic reduction. Typically, a preform is the shaped remnant of a lithic core. Larger and thicker than the intended tool, it lacks the final trimming and refinement that is present in the completed artifact. Sometimes basic features such as stems and notches have been initiated. In most cases, the term refers to incomplete projectile point.

See also

Indian sex stone.