The white South Sea pearls, Australian
Apart from the legends that tell how the pearl entered mythology, I would like to introduce the various types of pearls, specifically the most precious ones, the very large pearls that we sometimes see in jewelry shop windows and that are rightly presented as gems of inestimable value.
It is precisely this concept that early humans had of the pearl: a gift of nature, a precious talisman to possess that aroused desire.
Pearls are produced by oysters and are an integral part of their organism. The term pearl derives from the Latin “permula,” the name given to the shell that contains it and whose shape resembled the “thigh of a pig.”
There are two main families: freshwater pearls (pearls that are experiencing enormous growth both commercially and in selection) and saltwater pearls, which include Akoya pearls, Japanese pearls that generally do not exceed 9 mm in size and are usually White, Cream, Pink, and in their various shades.
South Sea pearls black, Polynesian pearls are very rare and precious, notable not only for their size but also for their color. Their size ranges from 9-10 mm up to 17-20 mm in valuable specimens with exorbitant prices.
The mollusk secretes a mother-of-pearl substance that varies from light gray to violet-black and is the only species that produces black pearls.
South Sea white pearls, Australian pearls.
In this article, I will discuss this type of pearl, the most precious white pearls, the largest that resemble marbles, whose wonderful story begins inside the mollusk called Pinctada Maxima. These pearls have an average diameter of 12-14 mm, but sizes can range from 10 mm up to 22-25 mm in specimens that are rarely seen as they are reserved only for the collector’s market.
In Australia, they are gathered exclusively in their natural environment, while in Indonesia and the Philippines, pearl oysters are farmed in nurseries.
This bivalve mollusk, protected and of a golden-silver color, varies in size from 10 cm for the young ones to over 25 cm for the adults and can weigh several kilos. It holds the record for being the largest pearl-producing mollusk, consequently producing very large pearls with a layer of nacre thicker than all others.
The first phase of cultivating Pinctada Maxima consists of fishing wild mollusks. After fishing, the shells are cleaned and selected: the minimum allowed size is 120 mm.
The second phase is the implantation of the nucleus, which begins in May or June and ends in September. The operation requires considerable experience and skill. A part of the mantle, the fleshy tissue adhering to the inner surface of the shell of a donor mollusk destined to be sacrificed, is cut out. This piece is then implanted into a chosen mollusk to form the pearl, placing a spherical and polished mother-of-pearl nucleus nearby. The cells of the mantle piece begin to reproduce, forming a pearl sac that envelops the nucleus. Layers of iridescent mother-of-pearl, called nacre, start to deposit around it: the cultured pearl begins its formation.
For the next two months, the oyster is regularly turned over on itself so that the pearl develops evenly.
During the approximately two years of cultivation, the shell is cleaned of marine encrustations to avoid damage to the mollusk.
Temperature is very important for pearl formation; the ideal is between 20 and 22 degrees Celsius. The higher the temperature, the more likely the pearl will grow large, sometimes sacrificing the orient, the layer of aragonite crystals that gives the pearl its shine and mirror-like effect, which adds value. Indeed, the best time for harvesting is the colder months from April to October, so the pearl will have a brighter surface layer.
Millions of oysters are cultivated each year, but only a tiny percentage can be destined for the market. Pearls cannot be considered a mass product obtained through an industrial process. Besides weather agents, parasites, and certain types of plankton that reduce oxygen in the bay water suffocating the oysters, at the end of the cultivation period, many pearls are too imperfect or flawed to be considered jewels. Consider that only 30% can be used, and only 2 or 3 of these will be perfect specimens.
After harvesting, the pearls are washed, graded, sorted by category, weighed in momme (a Japanese unit of measure used for pearls equivalent to 3.75 grams), and then sold at auctions.
By Fabrizio Ferro
By Fabrizio Ferro
