Wednesday, February 20, 2008

First International Pearl Convention


Emmanuel Fritsch of the University of Nantes (France) and Stefanos Karampelas of the University of Thessaloniki (Greece) attended the First International Pearl Convention in Abu Dhabi, United Arab Emirates (UAE), Nov. 19-20, 2007. Following is their report on some of the highlights:

Organized by the Dubai-based Pearl Revival Committee to raise the profile of natural pearls from the Persian Gulf (referred to locally as the "Arabian Gulf") and to discuss related issues, the conference included a seminar dedicated to technical issues and a summit focused on production and marketing.

Technical Seminar

Figure 1. These natural pearls, shown on a shell from the host Pinctada radiata, were recovered from the Persian Gulf. Photo by Nicholas Sturman.

Kenneth Scarratt (GIA Thailand) described the wide variety of mollusks that can produce pearls and argued that the term "pearl" should be applied to both nacreous and non-nacreous materials, such as conch pearls. He also told participants to "keep their minds open" to the theory that pearls may nucleate on a grain of sand, and displayed X-radiographs of pearls with minuscule shells in their centers. Elisabeth Strack (Hamburg, Germany) pointed out that natural freshwater pearls come from numerous locations, including lesser-known ones such as northwest Russia. She also discussed terminology and taxonomy issues (e.g., the vast majority of pearl "oysters" are actually not classified biologically as oysters). Shigeru Akamatsu (Mikimoto & Co., Tokyo) reviewed the history of pearl culturing. Among other issues, he discussed the present status of the Japanese akoya product, which is suffering from "red tides" and over-warm water temperatures. He said there are plans to move to a smaller but higher-quality production, mostly by limiting the number of pearl farms and number of shells under cultivation to reduce stress on the animals.

Nicholas Sturman (Gem & Pearl Testing Laboratory, Bahrain) reviewed pearl testing techniques, saying he prefers X-ray luminescence over measuring manganese content to separate freshwater from saltwater pearls. He also reminded the audience that production of natural pearls in the Persian Gulf (figure 1) is quite small today, with pearl fishing more a hobby than a commercial enterprise. Stephen Kennedy (Gem Testing Laboratory of Great Britain, London) reviewed pearl treatments and their detection, noting that some "chocolate" pearls, for example, are created by the bleaching and subsequent dyeing of gray-to-black pearls.

These contributors pointed out the importance of unsubstituted, short, polyacetylenic molecules ("polyenes") in the coloration of freshwater cultured and many other pearls, rather than carotenoids, which are found only in the pen-shell pearls of the genus Pinna. Sutas Singbamroong (Dubai Gemstone Laboratory, UAE) presented a preliminary study of Persian Gulf natural pearls, which are mainly small, white-to-"cream" colored (with about 2-3 percent yellow), and grow in a variety of shapes.

The technical seminar concluded with a panel discussion on how pearl certification can help the industry. Among other issues, the point was made that nacre quality is as important as nacre thickness. Lower-quality nacre can be recognized by its chalkier appearance, the defects it induces around drill holes and the presence of thicker-than-average conchiolin layers just beneath the surface, as seen in X-radiographs.


Figure 2. These 8+ mm cultured pearls were harvested in 2007 from the Sea of Cortez, Mexico. Photo by Douglas McLaurin.

A number of speakers addressed pearl production. Daniele Naveau (Robert Wan, Tahiti) discussed efforts to reduce the number of Tahitian farms in order to increase quality, in particular to ensure that nacre thickness exceeds 0.8 mm. Enrique Arizmendi (Perlas del Mar de Cortez, Guaymas, Mexico) described the history of natural pearl production in the Sea of Cortez, Mexico, which ended in 1914. Current efforts with the Pteria sterna have resulted in annual production of about 3.5 kg of multicolored cultured pearls (figure 2).

Three presenters addressed the incredible boom in Chinese freshwater cultured pearls: Shi Hongyue (Gems and Jewellery Trade Association of China), Dr. Qiu Zhili (SunYat-sen University, Guangzhou), and He Naihua (China's World Pearl Association). Production has risen from the first 0.61 kg of whitish "rice krispies" from Cristaria plicata in 1971 to the current 1,500 tons of larger, often colored cultured pearls from the Hyriopsis genus (an increase of more than a million-fold). Only about 5 percent of the cultured pearls are gem grade, and rounds represent less than 10 percent of the production. During the summit, Chinese delegates displayed several round white-to-purple freshwater cultured pearls of modest luster but very large size, about 17 mm. There is also a small production of saltwater cultured pearls from the Pinctada martensii (but the nacre is thin, 0.2-0.6 mm) and mabé from the Pteria penguin.

Stephen Arrow (Arrow Pearls, Broome, Western Australia) presented the history and current status of large South Sea cultured pearls from Pinctada maxima on the northwestern Australian coast. Good-quality rounds do not exceed 21 mm in diameter and require about six years of cultivation. Sarkis Hajjar (Belpearl, Antwerp, Belgium) discussed the culturing of pink-to-purple freshwater pearls in Lake Kasumiga, Japan, based on the hybrid Hyriopsis cumingii x H. schlegelii. About 10 kg of such pearls are produced annually, with other cultivation sites currently being sought.

Economics and Marketing

Both speakers on economics and marketing lamented the lack of reliable statistics for pearl jewelry and the industry. Tawfique Abdullah (Dubai Gold & Jewellery Group) regretted the poor communication between producers, manufacturers and retailers, and argued for harmonization of standards among the various producing regions. He added that the pearl industry spends less than one percent of the production value on promotion, as compared to the 20-40 percent spent by other luxury goods. Naheed Anees (ARY Academy of Gems & Jewelry, Dubai) pointed out that the Gulf Cooperation Council countries represent 9 percent of the world's jewelry market, and that per capita jewelry consumption in UAE is about 20 times the world's average. She recommended developing programs to educate consumers about pearls, in particular about imitations, which are still common in the Middle Eastern market. She also proposed developing effective marketing techniques to show that pearl jewelry is no longer "old-fashioned," but rather can be innovative as well as inexpensive.