pearl identification

[paul monfils]

Virtually any bivalve can produce a pearl. It is the way bivalves deal with irritating particles that get trapped in their soft parts and cannot be flushed out.  Someone in my area recently found a large purple pearl in a Venus Clam, Mercenaria mercenaria. However, many such pearls have no gem value because the outer surface of the pearl resembles the inner surface of the bivalve shell. A bivalve with a chalky white interior may coat an irritating sand grain and produce a pearl, but the pearl will be chalky white and not much to look at. The interior of Modiolus philippinarum is semi-nacreous and dark colored, so the pictured pearls may well have come from that species, but there is no way of knowing for sure.  <span class="petit">--Last edited by Paul Monfils on 2008-02-23 08:12:14 --</span>