Native American grinding stones are tools used by various tribes to grind seeds, nuts and foods such as corn into a paste that they baked and preserved. Native Americans also used other grinding stones as tools to sharpen the axes needed to cut timber for houses and for building canoes, for sharpening arrows used for hunting game animals, skinning hides, scaling fish and making weapons. They also ground plants into pastes used as dyes and paints.
The materials used for grinding stones are usually basalt, rhyolite, granite or some other locally available hard stone. In the Southwest, grinding stones used for grinding by hand are known as mano and metate. They range in size from small tools that grinders operated with one hand to larger devices that required two hands to operate. A smooth, hand-held mano resembling a pestle ground material using its smooth surface against a hard, flat stone containing a depression or small bowl that resembled a mortar and grew deeper with use.
Natives developed various grinding techniques ranging from circular rocking motions to chopping and grinding, depending on the material to be ground. The Pueblo tribes of the Southwest ground seeds, nuts, acorns and berries as well as maize for food. They also used these devices for pulverizing dirt and separating clay from which they crafted pottery.