Catalogue entry no. 585a by Max Loehr:
585 Pair of Thin, Chisel-like Slabs
Bluish gray, translucent, brown-flecked stone, cut into two flat, sharp-cornered, rectangular slabs. The perforations are slanting and rather imperfectly drilled. Because of their sharpened lower edges, the objects resemble chisels, but neither their material nor shape links them with the Chou chisels described above (Nos. 196, 197, 198, 199, and 200). Probably post-Han.