Bead-Cultured and Non-Bead-Cultured Pearls from Lombok, Indonesia

Sturman, Nicholas; Bergman, Jeffery; Poli, Julie; Homkrajae, Artitaya; Armstrong, Areeya; Somasa-ard, Nanthaporn

doi:10.5741/gems.52.3.288

Cited by 3 publications

(12 citation statements)

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“…Voids (type 4) and linear structures (type 5) have been reported as characteristic features in P. maxima NBC pearls (Sturman et al, 2016), but they were found in only ~5% and ~1%, respectively, of the natural pearl Figure 15. μ-CT slices in three directions of sample 6-8 revealed a complex elongated structure consisting of a linear-like feature at its center combined with dark gray areas of voids and organic matter, and other solid light gray areas.…”

Section: Discussionmentioning

confidence: 97%

“…While the identification of most NBC pearls is straightforward, differentiating between some natural and NBC pearls can be challenging because both types are formed almost entirely of nacre and do not contain a shell bead nucleus. The reports on P. maxima pearls from Western Australia (Scarratt et al, 2012) and Lombok, Indonesia (Sturman et al, 2016), are GIA's pioneering studies on pearls of known origin. The samples in both reports were classified as Btype samples since they were collected in situ from mollusks by GIA gemologists after the shells were recovered, and the information for each pearl retrieved is well documented.…”

Section: B2mentioning

confidence: 99%

“…Moreover, the central feature within the core has a linear form, and such features have been observed in NBC pearls produced by various mollusk species. Similar linear features, although not exactly the same, are often considered sufficient evidence to classify pearls as NBC (Hänni, 2006;Sturman, 2009;Krzemnicki et al, 2010;Sturman et al, 2016;Nilpetploy et al, 2018a;Manustrong, 2018). RTX and μ-CT imaging of samples 2-14 and 2-15 showed patchy concentric structures that appeared neither light nor dark gray, and these were due in part to differences in the organic content within the areas.…”

Section: Macro Image Rtx Image μ-Ct Imagementioning

confidence: 99%

“…The position of the pearl in the mollusk is indicated by a black arrow. (Wehrmeister et al, 2008;Sturman, 2009;Krzemnicki et al, 2010;Otter et al, 2014;Sturman et al, 2016;Nilpetploy et al, 2018a;Manustrong, 2018;Al-Alawi et al, 2020). In many cases, voids are a key identification feature by which to differentiate NBC from natural pearls.…”

Section: Macro Image Rtx Image μ-Ct Imagementioning

confidence: 99%

“…Owing to the different appearances of both types of formation, they are separated into different groups in this article. Linear structures have been regarded as characteristic of NBC pearls from both saltwater and freshwater environments (Scarratt et al, 2000;Sturman, 2009;Krzemnicki et al, 2010;Sturman et al, 2016;Nilpetploy et al, 2018a;Manustrong, 2018;Al-Alawi et al, 2020). Interestingly, 5 of the 774 natural pearl samples also displayed linear structures (table 7).…”

Section: Macro Image Rtx Image μ-Ct Imagementioning

confidence: 99%

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Internal Structures of Known Pinctada Maxima Pearls: Natural Pearls from Wild Marine Mollucks

Homkrajae¹,

Manustrong²,

Nilpetploy³

et al. 2021

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P earls are biogenic gem materials that may form naturally without human intervention, or with assistance from humans in a culturing process. Natural and cultured pearls often display similar external appearances and occasionally cannot be differentiated without examining their internal structures. Over the last century, scientists and gemological laboratories have used film X-radiography and digital real-time microradiography (RTX) to reveal these interior growth patterns (

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Section: Discussionmentioning

confidence: 97%

Section: B2mentioning

confidence: 99%

Section: Macro Image Rtx Image μ-Ct Imagementioning

confidence: 99%

Section: Macro Image Rtx Image μ-Ct Imagementioning

confidence: 99%

Section: Macro Image Rtx Image μ-Ct Imagementioning

confidence: 99%

See 3 more Smart Citations

Internal Structures of Known Pinctada Maxima Pearls: Natural Pearls from Wild Marine Mollucks

Homkrajae¹,

Manustrong²,

Nilpetploy³

et al. 2021

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Vietnam: Shell Nuclei, Pearl Hatcheries, and Pearl Farming

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et al. 2020

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Internal Structures of Known Pinctada Maxima Pearls: Cultured Pearls from Operated Marine Mollusks

Homkrajae¹,

Nilpetploy²,

Manustrong³

et al. 2021

G&G

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Pinctada maxima (the silver-or gold-lipped pearl oyster), Pinctada margaritifera (the blacklipped pearl oyster), and Pinctada fucata (martensii) ("the akoya pearl oyster") are the main mollusks of the Pinctada genus that are commercially farmed. They are routinely used to produce bead cultured (BC) pearls and, as a consequence, sometimes also produce non-bead cultured (NBC) pearls (Otter et al., 2014;Sturman et al., 2016;Nilpetploy et al., 2018a). P. maxima is the largest species in the genus (Scarratt et al., 2012) and generally requires a minimum two-year growth period to yield BC pearls with the thickest nacre layers of all BC pearls (Gervis and Sims, 1992; Cartier and Krzemnicki, 2016). Cultured pearls from the P. maxima mollusk are often referred to as "South Sea" in the market.Australia is the largest producer of white P. maxima (silver-lipped) cultured pearls, while Indonesia, Myanmar, and the Philippines are major producers of "golden" P. maxima (gold-lipped) cultured pearls. The farms producing these pearls are located between the Tropic of Cancer and the Tropic of Capricorn, which coincides with the native P. maxima mollusk's geographic distribution. The silver-lipped shells are found mostly south of the equator, while the gold-lipped shells populate the region north of the equator (Strack, 2006). P. maxima mollusks used for pearl culturing production in Australia are predominantly wildcaught shells collected in accordance with the annual quota that takes the shell sizes into account (between 120 and 175 mm shell length) and allows fishing

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Bead-Cultured and Non-Bead-Cultured Pearls from Lombok, Indonesia

Cited by 3 publications

References 0 publications

Internal Structures of Known Pinctada Maxima Pearls: Natural Pearls from Wild Marine Mollucks

Internal Structures of Known Pinctada Maxima Pearls: Natural Pearls from Wild Marine Mollucks

Vietnam: Shell Nuclei, Pearl Hatcheries, and Pearl Farming

Internal Structures of Known Pinctada Maxima Pearls: Cultured Pearls from Operated Marine Mollusks

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