Pique work {pique means pricked in French} used on small boxes,
cigarette cases and other small things. Round fine gold or
silver wire are hammered or inlaid in spaces cut in the surface.
Sort of like rivets. Other shapes may be able to be used if you
undercut the design a little and tap it into place. I have never
done it on ivory but i have done a similar thing on hardwoods. I
used small round wire and thin rolled out silver wire to create a
very intricate pattern for a knife handle. You can find a little
more info on this in Metal Techniques For Craftsmen by Oppi
Untracht. Big expensive book but well worth the money.