GIA and Paspaley Pearling Company conduct pearl expedition in Australia

Shedding light on advanced research of pearls, GIA (Gemological Institute of America) researchers from Thailand, undertook an expedition with the assistance of the Paspaley Pearling Company. The expedition led to Australia’s wild pearl oyster beds, which provided an opportunity to advance research into differentiating certain nacreous saltwater non-bead cultured pearls from natural pearls. GIA’s pearl research group and others in the pearl trade have focused on this sometimes difficult differentiation for decades.

In addition to thousands of laboratory analyses over the past few years, a major focus for both the GIA and Paspaley Pearling Company research teams has been establishing the most important criteria for present and future research: a reliable sample base of natural and cultured pearls of various types. While obtaining a definitive sample base for cultured pearls is straightforward, the rarity of natural pearls makes collecting a substantial sample base challenging.

Australia’s wild pearl oyster beds have been fished continuously since the mid-1800’s for Pinctada maxima, the world’s largest species of pearl oyster that has yielded many of the world’s large saltwater natural pearls. GIA’ choice of conducting research in Australia was due to the country’s seas being home to the world’s last commercially active fishery for wild Pinctada maxima oysters.

According to Kenneth Scarratt, GIA managing director for Southeast Asia, several recent expeditions by GIA into the waters off the rugged Northwest Coast resulted in the acquisition of many natural and cultured pearls that have produced excellent data that will enable GIA to establish impeccable test criteria for its pearl identification teams. “Resolving the issues involved in differentiating natural from saltwater non bead cultured pearls has been a focus of GIA’s research group for some time,” said Scarratt. “Meeting these challenges and using the results to serve GIA’s public benefit mission is what makes this kind of research so rewarding and important.”

A recent expedition that coincided with a Paspaley wild shell collection program focused on gathering large Pinctada maxima shell for use in the Mother of Pearl industry yielded the Institute’s most extraordinary results thus far.

In late September and early October, GIA pearl researchers Artitaya Homkrajae and Areeya Manustrong spent ten days aboard Paspaley’s diving ship MV Marilynne, during which they discovered and extracted 776 natural pearls from 20,488 large wild oysters. A majority of these pearls were small “seed” pearls, with the smallest measuring under 1mm in diameter, and the largest, a rare pearl measuring 16mm diameter. “This was a unique opportunity to gather specimens from an important and well-known source,” said Artitaya Homkrajae, GIA pearl researcher. “Establishing explicit provenance for the samples will support a great deal of further research,” added Areeya Manustrong. The 776 natural pearls, along with their shells are currently in GIA’s laboratory in Bangkok. Research on the same will be carried out in the following months. GIA will also prepare and publish a detailed report that will help clarify and establish clearer criteria for the interpretation of various data collected during the normal laboratory examination of pearls.