AU2013203092B2

AU2013203092B2 - A nucleus for pearl cultivation, and a method of production thereof

Info

Publication number: AU2013203092B2
Application number: AU2013203092A
Authority: AU
Inventors: Arthur Yick Cheong Wong; David Chun Kit Wong
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-01-10
Filing date: 2013-04-09
Publication date: 2014-11-27
Anticipated expiration: 2033-04-09
Also published as: PH12013000369A1; CN103918582A; CN106922582B; JP3189026U; AU2013203092A1; FR3000641B1; CN106922582A; PH12013000369B1; FR3000641A1

Abstract

Abstract A NUCLEUS FOR PEARL CULTIVATION, AND A METHOD OF 5 PRODUCTION THEREOF A method for making a nucleus for seeding a pearl in a pearl producing mollusc is disclosed, wherein the nucleus contains an RFID tag. The RFID tag allows the nucleus producer to be identified, as well as the oyster farmer and 10 the pearl produced. The produced pearl is therefore identifiable by RFID and the grade of the pearl as certified by industrial bodies may thereby be verified. Figure 2

Description

1 A NUCLEUS FOR PEARL CULTIVATION, AND A METHOD OF PRODUCTION THEREOF Field of the invention 5 This invention relates to the field of pearl production, including nuclei for seeding and cultivating pearls, and pearl identification. Background 10 Generally, a natural pearl is formed when a foreign object accidentally lodges into the mantle of a mollusc, such as an oyster. The oyster secretes nacre to encapsulate the foreign object in order to ease the irritation caused by the presence of the foreign object. If the foreign object is not removed, the oyster 15 will continue to secrete layer upon layer of nacre around the foreign object, which eventually forms a pearl. Nacre is about 90% calcium carbonate and 10% water and other organic substances, and appears as a smooth, hard crystalline substance composed 20 of microscopic crystals of calcium carbonate aligned perfectly with one another. The perfect alignment gives the requisite reflection and refraction, which makes a pearl appear iridescent.

2 Pearls are graded by assigning degrees to specific quality attributes, which are designated by authority groups such as GIA (Gemological Institute of America) and EGL (European Gemological Laboratory). 5 Two major grading systems are in fairly widespread use: the AAA-A system and the A-D system (Tahitian system). Both these systems are based on the 5 'virtues' of a pearl, namely lustre, size, shape, colour and spots. Lustre refers to light reflection. Size of the pearl is measured in millimetres. The shape of the pearl may be round, semi-round, oval, drop circle, button or 10 baroque, as desired. Spots refer to marks and cavities on the surface of the pearl. The AAA-A System grades pearls on a scale from AAA to A, with AAA being the highest grade: 15 AAA: Highest-quality pearl, virtually flawless. The surface has a very high lustre, and at least 95% of the surface is free from defect. AA: The surface has a very high lustre, and at least 75% of the surface is free from defect. 20 A: Lowest jewellery-grade pearl. Low lustre or more than 25% of the surface showing defects. Pearls that do not fall in a category but are between two may be graded accordingly, for example, A+ and AA+. 25 3 The A-D System (or Tahitian System) grades pearls on a scale from A to D, with A being the highest grade: A: High lustre and only minor imperfections over less than 10% of 5 pearl surface. B: High or medium lustre. Surface may have visible imperfections over no more than 30% of its area. C: Medium lustre. Surface defects over not more than 60% of the surface area. 10 D: Lustre is irrelevant. Defects over no more than 60% of its surface. Pearls below D grade are considered unacceptable for use in jewellery. 15 Sellers tend to expand on the systems in their own ad-hoc ways, such as by using terms from the grading systems to describe a pearl attribute different from that which the system is intended to grade. Some sellers even create their own grades such as "AAAA", to make it appear that the pearl is beyond the highest standard quality. Use of such self-concocted grades may be 20 simply dishonest. Both grading systems focus primarily on the lustre and surface quality of a pearl to determine its grade. There are, however, other attributes of a pearl that could contribute to the quality, which are not considered in these systems. 25 One of these is the quality of the nucleus in cultivated pearls. However, most 4 people, including pearl farmers and consumers, are often ignorant of the importance of pearl nucleus quality and the effects it has on the cultivated pearls. 5 The nucleus is typically a man-made irritant, which is typically a small round piece of shell, or a mother-of-pearl bead. The nucleus is implanted into an oyster, in a process called "nucleation," "grafting" or "seeding". The nucleated oyster is returned to the sea, where the oyster will secrete nacre to encapsulate the nucleus to produce a pearl, and will be harvested after 10 months to extract the cultivated pearl. Established standards require that pearl nucleus be made of nacreous substance with the same density as the pearl, and preferably made from pearl or shell material. Most commonly, pearl nuclei are made from the shells of 15 American Mississippi mussels in the size range of 1.8bu to 6.0 bu. A 'bu' is a standard for size used in the pearl industry where 1 bu = 3.03mm. Chinese freshwater shells are also generally accepted for use as nucleus material. However, there are pearls which are cultivated from sub-standard nuclei, and these pearls have poor quality and low value. An example of a sub-standard 20 nucleus material would be the shell of the Giant Clam, also known as Tridacna, the molecular structure of which makes it very brittle. Pearls cultivated from such brittle nucleus material are generally prone to cracking when the pearl is being drilled into for threading, causing significant monetary loss to the owner. 25 5 The thickness of the nacre also affects the quality of the cultivated pearl, particularly affecting the five 'virtues' discussed above, and also determines how durable, strong and long lasting could the pearl be. 5 Generally, the proportion of nacre is greater in a natural pearl than a cultivated pearl. After all, a natural pearl composes of nearly 100% nacre, while a cultivated pearl is composed of nacre covering the nucleus. This is despite that there may be around 1500 layers of nacre deposited on the nucleus in the period of 1 year. The nucleus implanted into the oyster is sometimes even 10 larger than a natural pearl, in order to enlarge to size of the cultivated pearl. The average consumer may be unaware of this, and has little or no means to look inside the pearl to determine the size of the nucleus, and is therefore exposed to deception by unscrupulous pearl traders. In some cases, even pearl farmers, pearl dealers, jewellers may be deceived. 15 A skilled person, however, may inspect the internal structure of a pearl visually under strong light, to examine the thickness and the fine sub-structure of the nacre. Any cracks, crevices, or blemishes in the nacre and the nucleus of a pearl could be visualized to some extent by this method. Natural and 20 cultivated pearls may also be differentiated by looking inside them under strong light, or by using x-ray radiograph or using optical coherence tomography (OCT). Cultivated pearls will show a narrow brown line around the nucleus, while natural pearls have no growth rings. However, all these methods require either skilled training or specialist equipment, which the 25 common consumer has little access to. Furthermore, these methods cannot 6 tell whether the nucleus itself is made of good quality nucleus material or not, and the consumer may be left to discover this at his own risk when the pearl cracks apart during drilling. 5 Therefore, it is difficult for a consumer to guard against buying a cultivated pearl with inferior nucleus, especially if the lustre and shape of the cultivated pearl seems appealing. It probably should be the pearl farmer who would know what was used as the 10 nucleus. However, most pearl farmers nowadays tend to buy nuclei from nuclei manufacturers and may be ignorant of the actual nuclei quality themselves. Furthermore, some effects of poor nucleus quality do not show up 15 immediately. Unstable nucleus material which could leak into the pearl nacre, affecting the quality of the pearl, may show up only when the pearl dries and shrinks over years. For reasons such as those discussed, it is desirable to propose a way of 20 accounting for the quality of pearls, the quality of pearl nuclei, oyster growth conditions, or the skills of the nucleation technician and so on. It is not admitted that any of the information in this patent specification is common general knowledge, or that the person skilled in the art could be 7 reasonably expected to ascertain or understand it, regard it as relevant or combine it in any way at the priority date. Statement of invention 5 In a first aspect, the invention proposes a method of producing a nucleus for pearl cultivation comprising the steps of: providing a first substrate, providing a second substrate, applying an RFID (radio frequency identification) tag on the surface of the second substrate, adhering the first substrate on the surface 10 of the second substrate, and processing the adhered substrates to give the adhered substrates a size, shape or texture for the cultivation of a pearl so that the adhered substrates have a size, shape and texture for the cultivation of a pearl. 15 The processing preferably includes shaping such as cutting. The processing may include polishing. Polishing changes the texture of the adhered substrates. 'Shaping' may include any of cutting the edges of the substrates, sanding, 20 carving or any other way of giving the adhered substrates a desired size or shape for the cultivation of pearls in molluscs, which shape is preferably but not necessarily, the shape of a generally round bead. Advantageously, shaping the nucleus after encapsulating an RFID tag 25 between the substrates require less time, effort and resources than if a 7a nucleus was formed into a rounded bead first, and then making a cavity in the rounded nucleus to contain an RFID. This is because nucleus material may be more prone to cracking under the stress of making the cavity than under the stress of shaping, or polishing. If the substrate cracked when the cavity is 5 being made, further efforts to shape the nucleus will no longer be required and 8 could be saved. On the other hand, if the nucleus was rounded or shaped first, and the subsequent making of the cavity caused the nucleus to crack, all the efforts in shaping the nucleus would be wasted. Furthermore, unshaped and unpolished substrates may be held more easily when making the cavity 5 than a rounded nucleus. Applying an RFID tag on the surface of the second substrate preferably comprises the steps of making a cavity in a surface of the second substrate; and placing an RFID tag into the cavity. However, 'applying' the RFID tag may 10 include printing the RFID tag on the surface of the second substrate, or any other way of securing an RFID tag to the second substrate. Optionally, the adhesive is epoxy. Alternatively, the adhesive may be other adhesive with similar properties to epoxy, including any one of: water-proofing 15 the RFID, not breaking down inside a pearl to affect pearl quality negatively, not reacting with nacre, not easily cracking or deforming under mechanical and thermal stress when the pearl is being drilled into. Preferably, the cavity is made such that it is positioned eccentric to the centre 20 of the nucleus, especially if the nucleus is a generally round bead. This helps to ensure the RFID tag in the nucleus is located eccentric to the centre of the cultivated pearl, and reduces the chance of drilling through the RFID tag when the pearl is being drilled through.

9 Possibly, the first and second substrates may even be made of the shell of Giant Clams. Giant Clam shell, usually not used for pearl nucleus because of endangered species protection, are not used mainly because the shell is too brittle to form a strong nucleus capable of withstanding cracking during pearl 5 drill through. However, the visual characteristics and quality of pearls cultivated from nuclei made of Giant Clam shell well surpass those pearls having nuclei made from of traditional freshwater shell, as nuclei made from Giant Clam shell tend to be very white in colour and can yield beautiful bright pearls. Advantageously, use of epoxy as an adhesive between substrate 10 layers of Giant Clam shell helps to mitigate the brittle quality of Giant Clam shell. In other words, use of epoxy to produce laminated layers of shell for making a pearl nucleus expands the choice and range of useable nucleus material. 15 In a second aspect, the invention proposes a pearl nucleus comprising an RFID tag held between two substrates. The nucleus used can be identified by the RFID tag. Typically but not necessarily, the substrates are made of the same material. An RFID tag has information which uniquely identifies the RFID tag. The nucleus can thereby be tracked to the nucleus manufacturer 20 who could be held accountable for the quality of the nucleus, the quantity of nuclei produced and so on. Preferably, the at least two substrates are adhered together by an adhesive such as epoxy. 25 10 Preferably, pearl nucleus is a rounded pearl nucleus. Preferably, the RFID tag is placed in a cavity made in at least one of the substrates, the cavity being eccentric to the centre of the surface of the 5 substrate. Optionally, the RFID tag is a passive one. However, the RFID tag is possibly an active RFID tag which further comprises a signal booster. This allows for stronger detection by a RFID reader, and allows loss or theft to be tracked. 10 In a third aspect, the invention proposes a pearl cultivated from a nucleus containing an RFID tag for identifying the pearl. The RFID tag allows the pearl to be identified by an RFID reader. Thus, the RFID can be matched to independent records of the pearl attesting to the pearl's quality and origins. If 15 the pearl is stolen or lost, the pearl can be detected or identified by RFID. In a fourth aspect, the invention proposes a method of identifying a pearl comprising the steps of: using an RFID reader to detect a signal from an RFID tag in a pearl, identifying the pearl from the signal. 20 Possibly, the steps further comprise determining the origin of the pearl based on the identification of the pearl. Possibly, the steps further comprise ascertaining the assigned grade of the 25 pearl based on the identification of the pearl.

11 In a fifth aspect, a system for pearl identification is proposed comprising: one or more pearls, each containing a uniquely identifiable RFID tag in the one or more pearls, a registry recording the grade of each of the one or more pearls, 5 one or more RFID readers for detecting the RFID tag inside each of the one or more pearls, wherein each of the one or more pearls is identifiable by RFID such that the grade of each pearl is retrievable from the register. The grade of pearls may be any of the 5 virtues of the pearl, origin, dates etc. 10 and preferably includes information indicating the quality of the pearl nucleus, the oyster farm in which the pearl is cultivated, the year of cultivation, the quality of the waters in the oyster farm and any other information useful for determining the quality of the pearl. 15 Also disclosed is a method of producing a nucleus for pearl cultivation comprising the steps of providing powdered shell, providing an RFID tag, and mixing the powdered shell with an adhesive to form a nucleus containing the RFID tag. Preferably the method includes rolling the powdered shell and adhesive into a nucleus containing the RFID tag. 20 Advantageously, this method allows waste shell from any shell processes to be re-cycled as pearl nuclei, particularly powdered shell. This method obviates or reduces the efforts to cut a non-round nucleus substrate, and the efforts to shape and polish a nucleus into a rounded bead. Furthermore, this method 25 allows previously unfavourable shell material, such as brittle Giant Clam shell, 12 to be used as nucleus material. This is because epoxy is capable of holding the powdered shell together strongly to withstand cracking of the nucleus when the cultivated pearl is being drilled through. 5 The term "comprises" and its grammatical variants has a meaning that is determined by the context in which it appears. Accordingly, the term should not be interpreted restrictively unless the context dictates so. Drawings 10 It will be convenient to further describe the present invention with respect to the accompanying drawings that illustrate possible arrangements of the invention, in which like integers refer to like parts. Other embodiments of the invention are possible, and consequently the particularity of the accompanying 15 drawings is not to be understood as superseding the generality of the preceding description of the invention. Figure 1 illustrates a first step in a method of production of a pearl nucleus; 20 Figure 2 illustrates a second step to the method of production of a pearl nucleus of Figure 1; Figure 3 illustrates an RFID tag used in the method of production of a pearl nucleus of Figure 2; 25 13 Figure 4 illustrates a further step to the method of production of a pearl nucleus of Figure 1; Figure 5 illustrates a further step to the method of production of a pearl 5 nucleus of Figure 1; Figure 6 illustrates yet a further step to the method of production of a pearl nucleus of Figure 1; 10 Figure 6a is a photograph of a pearl nucleus made in accordance to the method of production of a pearl nucleus of Figure 1 to Figure 6; Figure 6b is an illustration of the pearl nucleus of Figure 6a; 15 Figure 6c illustrates a system of identifying pearls using the pearl nucleus; Figure 7 illustrates a first step in an alternative method of production of a pearl nucleus; and 20 Figure 8 illustrates a second step in the method of production of a pearl nucleus of Figure 7.

14 Description of Embodiments Figures 1 to 6 show a method of making a nucleus for seeding a mollusc, such as an oyster or any other appropriate shell fish, to obtain a cultivated 5 pearl. A nucleus for seeding an oyster is prepared from a first substrate 101 and a second substrate 103. The first substrate 101 and a second substrate 103 are made of a suitable seeding material, such as the shell of a freshwater clam 10 105. Figure 2 shows a cavity 201 carved into a surface of the second substrate 103. The depth and area of this cavity 201 is sized to able to contain a small RFID (radio frequency identification) tag 301, preferably in a snug manner. 15 RFID is a technology which uses wireless non-contact systems, such as radio-frequency electromagnetic fields, to obtain data from an RFID tag attached to an object. An RFID tag typically has a unique identity, which allows the attached object to be identified. 20 Generally, an RFID tag 301 includes a small RF transmitter and receiver detect-able by a two-way radio transmitter-receiver called an RFID reader. An RFID reader transmits a radio signal to interrogate, or detect, any RFID tag within nearby vicinity. Any such RFID tag within the vicinity reflects the radio 25 signal along with the tag's RFID identity to the RFID reader.

15 RFID tags 301 can be either passive or active. An active RFID tag 301 has an on-board battery which can amplify the response signal to the RFID reader, such that the signal can reach the RFID reader over a greater distance. A 5 passive RFID tag 301 is cheaper and smaller but the RFID reader must be relatively closer to detect the passive RFID tag 301. The RFID tag 301 used in this embodiment is a small one, such as that of IM5-PK2525 made by Hitachi Chemical Co. Ltd., as illustrated in Figure 3. 10 Figure 3 is taken from Hitachi Chemical Co Ltd, http://www.hitachi chem.co.jp/english/products/ppcm/files/im5 pk2525.pdf, and shows the RFID tag 301 and the tag's antenna for receiving and transmitting signals. The specific details of an RFID tag 301 are known to the skilled man and are not necessary for elaboration here. It suffices to note that the dimensions of the 15 RFID tag 301 is 2.5mm x 2.5mm x 0.4mm in this embodiment, which allows the cavity 201 in the substrate nucleus to be considered small. Figure 4 shows that the surface of the second substrate 103 around the cavity 201 being laid over with a suitable adhesive 401. 20 Figure 5 shows that the first substrate 101 subsequently placed over the adhesive 401 on the surface of the second substrate 103 to form a laminated structure, illustrated in the form of a laminated cube 501. The RFID tag 301 is therefore placed between the first substrate and second substrate, within the 16 laminated cube 501. Together, the adhesive 401, the first substrate 101, and second substrate 103 waterproof the encapsulated RFID tag 301. The adhesive 401 is preferably epoxy, or any similar polymer. On application 5 and curing, epoxy acts as the adhesive 401 binding the first substrate 101 and the second substrate 103, and the RFID tag 301 together. Epoxy is tough and is likely to withstand drilling impact and heat, without cracking or breaking apart. Furthermore, epoxy is stable not subject to degradation easily. 10 The laminated cube 501 formed from adhering the first substrate 101 and the second substrates 103 is then treated and processed as per conventional pearl nucleus manufacturing methods. That is, if the laminated cube 501 is large, the corners of the laminated cube 501 are cut to reduce the size of the laminated cube. Subsequently, the size-reduced laminated cube 501 is then 15 polished by steel and diamond powders in a grinding plate commonly known in the trade by the Japanese name "enban", to produce a generally smooth and round bead 601 as illustrated in Figure 6. The round bead may be used as a nucleus 601 for cultivation of pearls. 20 Although it is not necessary that the nucleus 601 is round, it is preferable as the extent of the roundness and smoothness of the nucleus 601 determines the final shape of the pearl to be produced. In contrast to the above steps, it would be more difficult to make a cavity in an 25 already rounded and polished nucleus, and then inserting an RFID tag 301 17 into the cavity and sealing the cavity. If the already rounded nucleus cracked when the cavity is being made, the energy and effort spent to shape and polish the nucleus would all be wasted. 5 Therefore, it is advantageous to encapsulate the RFID tag 301 between layers of unshaped substrates, and only cutting, shaping and polishing the substrates after the substrates are laminated and adhered together. Furthermore, a non-rounded substrate can be held more easily for making a cavity in the substrate. In addition, laminating and polishing efforts could be 10 applied only to substrates which did not crack when the cavity 201 is made. To grind the nucleus into a rounded bead without breaking the RFID tag 301 requires menial skills on the part of human technicians and is not part of this embodiment. 15 Figure 6a is a photograph of a nucleus 601 made according to the above steps. The line showing the division between the two substrates used to encapsulate an RFID tag inside the nucleus 601 is almost unnoticeable. 20 Figure 6b is an illustration of Figure 6a showing the nucleus 601 is a laminate of a first substrate 101 and a second substrate 103, which is rounded into a bead.

18 The small dimensions of the RFID tag 301 allow the nucleus 601 to be small, and the lower size limit of the cultivated pearl is therefore low. Thus, the cultivated pearl does not have to be big. 5 Typically, the nucleus may be as small as 0.9 bu if the RFID tag 301 has a dimension of 2.5mm x 2.5mm x 0.4mm. Alternatively, RFID tags 301 of other sizes may be used as the situation requires or permits. The adhesive 401 prevents water from seeping between the first substrate 10 101 and second substrate 103, and prevents the RFID tag 301 from contacting water when planted into an oyster. This prevents corrosion of the RFID tag 301. Also, the adhesive 401 prevents material in the RFID tag 301 from leaking out of the nucleus 601 into nacre deposited around the nucleus 601. Without a suitable adhesive 401, the pearl quality could be affected if the 15 RFID material leaks into the nacre, even years after the pearl has been purchased. The location of the cavity 201 in the second substrate 103 is preferably nearer to any one side of the surface of the second substrate 103, and not at the 20 centre of the surface of the second substrate 103. This decreases the chance of the RFID tag 301 being situated right in the middle of the cultivated pearl as the pearl forms, which reduces likelihood of damage when the pearl is being drilled through the pearl's centre. In general, the probability of damage due to drilling decreases as the size of the nucleus increases (volume of sphere = 25 4/3 pi * r^3). Also, locating the RFID tag 301 closer to one side of the pearl 19 increases RFID signal readability, as the response signal needs to transmit through less nacre on that side of the pearl. When the nucleus 601 is ready, a live mollusc such as a pearl oyster is 5 surgically opened and the nucleus 601 is inserted into the oyster. The details of the surgery and incision are well known to the skilled man and are performed by highly skilled technicians, and need not be described here. The oyster is then returned to the water for several months of care, in order to cultivate a pearl. 10 After some time, sufficient nacre laid around the nucleus 601 to form a pearl which may be harvested. The pearl is capable of being drilled through for threading without cracking easily as the nucleus 601 can withstand the drilling heat and impact, due partly to the adhesive 401 used, preventing the pearl 15 from cracking apart under the thermal and mechanical stress of drilling. The RFID tag 301 in the cultivated pearl is capable of responding through the layers of nacre to probing signals from an RFID reader, and the pearl containing the RFID tag 301 is now identifiable by the unique identity of the 20 RFID tag 301. The pearl may then be sent for quality inspection and for grading by a qualified person. The grade of the pearl may subsequently be recorded in a register along with the RFID of the pearl. Preferably, but not necessarily, the 25 register may be accessible online.

20 In general, the grade of the pearl may be based on conventional pearl attributes such as the aforementioned 5 virtues. If desirable, however, the grade of the pearl may include a description of the growth conditions of the 5 oyster, the quality of the farming waters, the exact period over which the oyster is farmed and the pearl is left to grow, the quality and type of nucleus used, the thickness of the nacre and so on. Figure 6c illustrates how, after the cultivated pearl 605 is released into the 10 market, any trader of pearls may now used a suitable RFID reader 603 to detect, at 604, the identity of the cultivated pearl 605, and search for the established grade of the cultivated pearl 605 in a registry or database 607, including the quality and origin of the cultivated pearl 605 and the pearl nucleus 601. 15 RFID readers 603 are cheap and widely available, and can be easily used by any jeweller for reading the RFID tag 301 in the cultivated pearl 605. This allows both trader and consumer to identify the pearl 605 and the quality thereof easily, without need of specialist instruments to look inside the pearl 20 605. Figure 7 shows an alternative embodiment of the invention. Shell material 701, such as that of the American Mississippi mussel, is grounded into powder 703. Mixing with a suitable binder or adhesive, such as epoxy, the 25 shell powder 703 is shown in Figure 8 as formed into a nucleus bead 801 21 containing an RFID tag 803. The skilled man understands that epoxy requires curing. This method obviates the need to grind the surface of a laminated nucleus to make it round. Furthermore, this method allows the use of the shell of the Giant Clam, or other brittle shells, as long as the adhesive 401 is 5 capable of ensuring that the pearl nucleus is so well bound that it does not crack easily during pearl drill through. The adhesive 401 ensures that the RFID tag 803 inside the bead is waterproofed. Furthermore, use of the adhesive 401 prevents the leakage of RFID material into the nacre, and also prevents corrosion of the RFID tag 803 when the oyster containing the 10 laminated nucleus is submerged into water. Pearl farmers and consumers are often ignorant of the effects of pearl nucleus 601 on the quality of cultivated pearls 605. This may now be mitigated to some extent by the described embodiments. The RFID identifiable pearl 15 nucleus and RFID identifiable pearl as described will allow manufacturers of pearl nuclei to be traced, imposing accountability on the manufacturers for the quality of both pearl nuclei and, to some extent, cultivated pearls. In this way, the embodiments allow pearl oyster farmers to identify dubious or sub standard manufacturers. 20 Furthermore, the farmer himself may also be tracked by the nuclei 601 he purchased or used. The consumer will benefit in particular because the embodiments possibly 25 allow the consumer to retrieve from a database 607 objective information on 22 the quality of a pearl 605, and reduces the possibility of the consumer being deceived. The RFID could also allow a pearl to be tracked for security reasons, such as 5 in the event of theft or at the customs of a country. Accordingly, the embodiments described include a method of producing a nucleus 601 for pearl cultivation comprising the steps of: providing a first substrate 101, providing a second substrate 103, applying an RFID (radio 10 frequency identification) tag on the surface of the second substrate 103, adhering the first substrate 101 on the surface of the second substrate 103, and shaping the adhered first substrate 101 and second substrate 103 into a suitable shape for use as a nucleus 601. 15 Furthermore, the embodiments described include a system for pearl identification comprising: one or more pearls 605 each containing a uniquely identifiable RFID tag 301 in the one or more pearls 605, a registry record 607 of the grade of pearls 605, RFID readers 603 for detecting the RFID tag inside the pearls 605, whereby the pearls 605 are identifiable and the grade of the 20 pearls 605 may be searched in the register 607. Furthermore, the embodiments described include a method of producing a nucleus 601 for pearl cultivation comprising the steps of providing powdered shell 703, providing an RFID tag 301, mixing the powdered shell 703 with an 23 adhesive 401, rolling the powdered shell 703 and adhesive 401 into a nucleus containing the RFID tag 301. Furthermore, a pearl nucleus has been described which comprises at least 5 two substrates adhered together to encapsulate an RFID tag 301. While there has been described in the foregoing description preferred embodiments of the present invention, it will be understood by those skilled in the technology concerned that many variations or modifications in details of 10 design, construction or operation may be made without departing from the scope of the present invention as claimed. For example, although the RFID tag is described as implanted into a cavity 201 made in the second substrate 103, the RFID tag may instead be printed 15 on the surface of any one of the first substrate 101 and second substrate 103 and sandwiched between. In this case, there is no need to make a cavity in any of the substrates. The first substrate 101 and second substrate 103 may be made of any 20 suitable material for causing nacre secretion in an oyster. Preferably, however, at least one of the first substrate 101 and the second substrate 103 may be made of mother-of-pearl or broken pearl pieces. The first substrate 101 and the second substrate 103 may both be made of the same material, or may be each made of different material. 25 24 Although, oysters were mentioned in the embodiments as the nacre producing creature, the skilled man understands the embodiments are intended to include other types and species of molluscs and shellfish capable of secreting nacre, including freshwater or sea water oysters. 5 Although the shell used for pearl nucleus is mentioned as taken from the American Mississippi fresh water mussel, the technician understands that other shells may be used, such as the Chinese freshwater shell, or from even the shells of the Giant Clam may be used as long as the adhesive 401 holds 10 the substrates together when the pearl is being drilled through. Although pearls have been described which contain an RFID nucleus made according to the embodiments, pearls containing RFID identifiable nucleus made by ways other than those of the specific embodiments are intended to 15 be included within the scope of the description.

Claims

1. A method of producing a nucleus for pearl cultivation comprising the steps of: 5 providing a first substrate; providing a second substrate; applying an RFID tag on the surface of the second substrate; adhering the first substrate on the surface of the second substrate; and processing the adhered substrates to give the adhered substrates a 10 size, shape or texture for the cultivation of a pearl so that the adhered substrates have a size, shape and texture for the cultivation of a pearl.

2. A method of producing a nucleus for pearl cultivation as claimed in claim 1, wherein applying an RFID tag on the surface of the second substrate 15 comprises the steps of: making a cavity in a surface of the second substrate; and placing an RFID tag into the cavity.

3. A method of producing a nucleus for pearl cultivation as claimed in claim 2, 20 wherein the cavity is made such that it is eccentric to the centre of the nucleus.

4. A method of producing a nucleus for pearl cultivation as claimed in anyone of claim 1, 2 and 3, wherein the adhesive is epoxy. 25 26

5. A method of producing a nucleus for pearl cultivation as claimed in any one of claims 1 to 4 wherein the processing includes shaping.

6. A method of producing a nucleus for pearl cultivation as claimed in claim 5 5 wherein the processing includes cutting.

7. A method of producing a nucleus for pearl cultivation as claimed in any one of claims 1 to 6 wherein the processing includes polishing. 10

8. A pearl nucleus comprising an RFID tag held between two substrates.

9. A pearl nucleus as claimed in claim 8 wherein the at least two substrates are adhered together by epoxy. 15

10. A pearl nucleus as claimed in claim 8 or claim 9 which is a round pearl nucleus.

11. A pearl nucleus as claimed in claim 8 wherein the RFID tag is in a cavity made in one of the substrates, the cavity being eccentric to the centre of 20 the pearl nucleus.

12. A pearl cultivated using a nucleus containing an RFID tag for identifying the pearl; wherein the nucleus is a laminated nucleus comprising at least two 25 substrates adhered together, and the RFID is between the two substrates. 27

13. A cultivated pearl as claimed in claim 12 wherein the at least two substrates are adhered by epoxy. 5

14. A method of identifying a pearl comprising the steps of: using an RFID reader to detect a signal from an RFID tag inside a pearl; identifying the pearl from the signal; wherein the RFID tag is held between two substrates forming a pearl nucleus. 10

15. A method of identifying a pearl as claimed in claim 14 further comprising the steps of: certifying the grade of the pearl based on the identification of the pearl. 15

16. A method of identifying a pearl as claimed in claim 14 or 15 further comprising: determining the origin of the pearl nucleus used to cultivate the pearl based on the identification. 20

17. A system for pearl identification comprising: one or more pearls, each containing a uniquely identifiable RFID tag; the RFID tag in each of the one or more pearls being held between two substrates forming a pearl nucleus; a registry recording the grade of each of the one or more pearls; 28 one or more RFID readers for detecting the RFID tag inside each of the one or more pearls; wherein each of the one or more pearls is identifiable by RFID such that the grade of each pearl is retrievable from the register. 5

18. A method of producing a nucleus for culturing a pearl substantially as described in the description or illustrated in the drawings.

19. A pearl nucleus as substantially as described in the description or 10 illustrated in the drawings.