Sourcing carbonate pointed stones from the barrier beach of Mantoloking, New Jersey, USA

Over 500 previously unidentified, symmetric pointed stones of similar size, shape, color, and texture have been found on the barrier beach of Mantoloking, New Jersey, since 1940. Petrographic, stereo, and scanning electron microscopy analysis reveals that the stones are made of either a biomicritic packstone composed of 50% siliceous microfossil remains ( including sponge spicules and radiolaria) embedded in a micrite matrix or a limestone with abundant angular quartz grains (50–150 μm wide) surrounded by a calcite matrix. The distinctive shape of the Mantoloking stones is most similar to whetstones used for sharpening scythes. We conducted a worldwide search and discovered one producer of carbonate whetstones: a company in the town of Pradalunga in Northern Italy. Microscope analysis reveals that the Pradalunga source rocks are exact matches for the spicule‐rich limestone and angular quartz‐rich limestone found in the Mantoloking collection. The whetstones are most likely lost cargo from a wreck offshore of Mantoloking, but the exact source may never be known. © 2006 Wiley Periodicals, Inc.