Jim,
Why would do you think this is a chip as opposed to piece of scrimshaw used for jewelry. Either way if you search google, he seems to be a known scrimshaw artist. Here's one on ebay:
http://cgi.ebay.com/Nautical-Scrimshaw-Fossil-Ivory-Mounted-display_W0QQitemZ7363620959QQcategoryZ63619QQssPageNameZWDVWQQrdZ1QQcmdZViewItem