Fig. 2.

Usewear patterns from S14 grinding stones. (Magnification: 200×) (1 and 2) GS1, fine striations running diagonally and a polished crystal surface, resembling tuber processing. (3) GS2, small pitting (right), short furrows (lower left), and very fine and faint striations running vertically (upper left), likely related to pounding small, hard objects, abrading stone objects, and processing plants, respectively. (4) GS3-P1, a medium level polished area, similar to tuber processing. (5) GS3-P2, sleeks running vertically, similar to dry bean or large seed processing. (6) Uneven surface of natural crystals on an unused sandstone, for comparison with used tools.