pearl identification

[water]

Hi everybody  <img src="images/smiley/smile.gif" alt="" border="0" />. My first time on this forum. I would need your comments on the attached photo. Those, mostly dark purple nacreous pearls, ranging from approx. 2mm to 6mm are presented as coming from the Modiolus philippinarum shell. As anybody ever come accross natural pearls from this shell ?
Many thanks

Water
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