World Of Gems Conference 2017 Proceedings Book

PEARLS, THEIR MOLLUSKS AND TREATMENTS P earls are one of the most diverse and unique gem mate- rials available to jewelers. Not only are they organic, put- ting them in a small but select group of materials used in the trade, but they also occur in an amazing array of colors, shapes and types (nacreous, porcelaneous, non-nacreous, salt- water, freshwater). Although any mollusk has the potential to produce a pearl only a limited number produce pearls in com- mercial quantities and these tend to be those from the Pteriidae family which includes the two most important genera; Pinc- tada and Pteria . Other more “exotic” pearls such as the regal conch, impressive melo and extremely colorful abalone (Figure 1) only add to the vari- ety available. This bountiful range provides jewelers and ar- tisans around the globe with a never-ending supply of material with which to work their magic. The end product is only limited by their imagination yet the very nature of the organic gems allow free-flowing de- signs to grace the necks, hands and bodies of women in our modern world. Yet pearls are not only synonymous with women, some men have also been captivated by pearls and whether as a symbol of power and rank, Gaikwar of Baroda, or to deviate from the “norm”, StevenTyler of Aerosmith, they have been used by both genders to make a statement. However, pearls are most often associated with women and as a result form an important part of virtually every woman’s jewelry collection. History has recorded this fact and highlighted their popularity via countless images and film footage. From Queen Cleopatra to Queen Elizabeth II, Maisie Plant to Countess Mona Von Bismarck, and Gina Lollobridgida to Elizabeth Taylor, pearls are probably a girl’s second best friend to diamonds! The tradi- tional white nacreous pearls are a common sight on women whenever formal occasions are called for while more colorful and plentiful pearls in the form of nacreous freshwater pearls are often seen on women of all generations when enjoying more informal occasions. Pearls allow for all tastes and all occasions, as well as all budgets. The great variety of colors seen in pearls allow people to mix and match with their clothes and other accessories on a daily basis, and while the layperson often associates and believes that pearls are limited to white and cream, more vibrant yel- lows and orangy yellows are produced by Pinctada maxima or Pinctada maculata mollusks of the Far Eastern oceans, while a range of more pastel- like pink, orange, purple and vi- olet colors are produced by Unio species mollusks origi- nating from freshwater bodies around the world. Yet, while these colors may be natural there are plenty of treated pearls on the market whose color is not all quite what it seems. Their colors did not originate naturally as a conse- quence of the genes within the shells that produced them but rather through the addition of artificial colors post-harvest. Treatments of all kinds are ap- plied to pearls in order to improve their appearance and ulti- mately their marketability. Some of these treatments are detectable and need to be disclosed while others are generally accepted by the trade and considered “routine” so do not need disclosure. In the end all that is required, and expected, in today’s more regulated market is full disclosure whenever a dis- closable treatment is known to exist. Whether pearls are natural or cultured, untreated or treated, the fact remains that this wonder of nature is one of the most popular gem materials that exists in the market and there is no reason why this status will not continue for the foreseeable future. u WORLD OF GEMS CONFERENCE V - 11 - SEPTEMBER 2017 Nicholas Sturman, FGA, DGA PEARLS ABSTRACT FIGURE 1. An abalone (Haliotis species) shell together with a natural abalone pearl. These shells and their pearls have to be the most colorful of all the mol- lusks and pearls! Photo by Nuttapol Kitdee, © GIA.