Groundstone artifacts comprise an artifact class with numerous forms and functions.  The broadest definition of groundstone is stone that has been pecked or ground into a specific shape.  Groundstone artifacts are most commonly associated with sites post-dating the terminal Pleistocene/early Holocene (approximately 8,000 years ago), when a greater emphasis on plant resources became common in the Southwest.  Groundstone artifacts are by no means as diagnostic as ceramic types and projectile points; however, morphological and raw material source studies have resulted in the identification of manufacturing locations, and in some instances, cultural affiliations.  Groundstone artifacts common to the Southwest include manos and metates, mortars and pestles, shaft abraders, palettes, axes and mauls, and a variety of other artifact types, many of which are included in the American Southwest Virtual Museum.