This thing came across the packing table today. Whatever it was, it must have gotten trapped inside an oyster and then covered with nacre. Diana suggests it might have been a barnacle... and despite the fact that barnacles are especially difficult sea creatures to relate to, the thought of being swallowed alive by an oyster and then slowly encased in shell is pretty creepy.
See our earlier "ugliest pearl" entries here. And it says a lot about the quality of pearl produced by Pacific oysters that we haven't bothered to start a "most beautiful pearl" contest...