Pearl Production

Does the quality of cultured pearls from the black-lip pearl oyster, Pinctada margaritifera, improve after the second graft?

“…Pearl oysters that produce good quality pearls are generally considered for further nucleus implantation(s) to produce a second, third or even fourth cultured pearl, depending on their health and continued ability to produce good quality pearls (Fong et al, 2005;Taylor and Strack, 2008). These 're-seed' of 're-graft' operations are called 'surgreffe' in French Polynesia and involve insertion of a nucleus into the existing pearl-sac formed during the previous graft (Taylor and Strack, 2008).…”

“…Pearl grafting is usually performed by skilled technicians that commonly work only with a single species of pearl oyster. After the grafting operation, saibo tissue proliferates to form a pearl-sac, which envelopes the nucleus, and nacre secreting epithelial cells from the pearl-sac begin to deposit nacre onto the nucleus (Cochennec-Laureau et al, 2010;Dix, 1972;Kishore and Southgate, 2015;Scoones, 1996;Taylor and Strack, 2008). For the black-lip pearl oyster, Pinctada margaritifera, a culture period of approximately 18 months is required before a commercially acceptable nacre thickness of 0.35-0.8 mm (Haws, 2002;Matlins, 2002;Ruiz-Rubio et al, 2006;Southgate et al, 2008) is achieved and the resulting cultured pearl is ready to be harvested.…”

“…Pearls are produced when a piece of mantle tissue (saibo) from a foreign (donor) pearl oyster and a round inorganic nucleus are inserted into the gonad of a host pearl oyster (Gervis and Sims, 1992;Taylor and Strack, 2008); a process known as 'seeding' or 'grafting'. Pearl grafting is usually performed by skilled technicians that commonly work only with a single species of pearl oyster.…”

Influence of Imidazole Carboxylic Acid-Nickel Complex on the Nacre Color in Pearl Oyster

“…In artificial culture, pearls are produced in a process that lasts approximately 20 months [4]. Artificial pearls represent a highly valued export industry.…”

The Use of Probabilistic Neural Network and UV Reflectance Spectroscopy as an Objective Cultured Pearl Quality Grading Method

“…A PNN is predominantly a classifier that combines attributes of statistical pattern recognition and feed forward artificial neural networks [4]. In the past decade the ANN modeling technique has found applications for recognition and classification of spectra from a variety of spectroscopic methods [5][6][7][8][9]. Different network architectures, including a MLP, radial basis function (RBF), self-organizing map (SOM), and probabilistic neural network (pnn), have been proposed for classification purposes.…”