Scrimshaw

v. t.	1.	To ornament, as shells, ivory, etc., by engraving, and (usually) rubbing pigments into the incised lines.
n.	1.	A shell, a whale's tooth, or the like, that is scrimshawed.

Noun

1.

scrimshaw - a carving (or engraving) on whalebone, whale ivory, walrus tusk, etc., usually by American whalers

carving