Catalogue entry no. 210 by Max Loehr:
210 Large Trapezoidal Knife with Dentations
Dark gray-green stone with black areas and light markings. The back is straight, but slants irregularly near the right edge, which has rounded corners. The faces slope down to a concave, blunt cutting edge. The left edge of this large tool is decorated with symmetrically carved pairs of transversally grooved teeth, projecting from two low ridges which are divided by a notch. Parallel to the back is a row of four conical perforations of the same size and drilled from the same side. On the reverse side is an elliptical depression, indicating a flaw in the original slab. Shang or Western Chou(?).