Grinding slab

{{Short description|Prehistoric stone tool}}

image:Acorn grinding stone-750px.jpg

In archaeology, a grinding slab is a ground stone artifact generally used to grind plant materials into usable size, though some slabs were used to shape other ground stone artifacts.{{Cite journal |last1=Shoemaker |first1=Anna C. |last2=Davies |first2=Matthew I.J. |last3=Moore |first3=Henrietta L. |date=2017 |title=Back to the Grindstone? The Archaeological Potential of Grinding-Stone Studies in Africa with Reference to Contemporary Grinding Practices in Marakwet, Northwest Kenya |journal=African Archaeological Review |language=en |volume=34 |issue=3 |pages=415–435 |doi=10.1007/s10437-017-9264-0 |issn=1572-9842|doi-access=free }} Some grinding stones are portable; others are not and, in fact, may be part of a stone outcropping.

Grinding slabs used for plant processing typically acted as a coarse surface against which plant materials were ground using a portable hand stone, or mano ("hand" in Spanish). Variant grinding slabs are referred to as metates or querns, and have a ground-out bowl. Like all ground stone artifacts, grinding slabs are made of large-grained materials such as granite, basalt, or similar tool stones.