Pearls of all kinds have been used for decorative purposes throughout history. The majority of these have been nacreous, yet certain non-nacreous pearls have also been sought by connoisseurs. Pinna (pen) pearls fall into the latter group. The nature of their non-nacreous structure often results in cracking, and because of stability concerns they are very rarely used in jewelry. Nineteen of the 22 samples from this study, reportedly from Pinnidae family mollusks, show similarities in color as well as external and internal structure. Raman, photoluminescence, and UV-Vis-NIR spectroscopic results are discussed, along with the internal characteristics of pearls likely produced by this mollusk.
The Pinnidae family i...
Pearls of all kinds have been used for decorative purposes throughout history. The majority of these have been nacreous, yet certain non-nacreous pearls have also been sought by connoisseurs. Pinna (pen) pearls fall into the latter group. The nature of their non-nacreous structure often results in cracking, and because of stability concerns they are very rarely used in jewelry. Nineteen of the 22 samples from this study, reportedly from Pinnidae family mollusks, show similarities in color as well as external and internal structure. Raman, photoluminescence, and UV-Vis-NIR spectroscopic results are discussed, along with the internal characteristics of pearls likely produced by this mollusk.
The Pinnidae family is widely distributed among the oceans of the world, from the Mediterranean to the Red Sea, the Arabian Gulf, and the Indo-Pacific (from southeastern Africa to Melanesia and New Zealand, extending north to Japan and down to New South Wales). In the Western Hemisphere, these mollusks inhabit American waters around Florida, North Carolina, and Texas, as well as Mexico, the Caribbean, and as far south as Argentina (Strack, 2006). One of the authors’ diving adventures in the Arabian Gulf off the coast of Bahrain (Sturman et al., 2010) revealed numerous specimens deeply embedded within the sandy floor, typical of the mollusk’s behavior.
