Pearls occur in seven basic shapes in nature. These are 1) round 2) near-round 3) oval 4) button 5) drop 6) semi-baroque and 7) baroque. The GIA classifies pearl shapes into three main categories. They are :- 1) Spherical 2) Symmetrical and 3) Baroque.
1) Spherical - Spherical pearls have a uniform or near-uniform diameter all round and several lines of symmetry through which the pearl can be divided into two equal halves. Round and near-round pearls come under this category.
2) Symmetrical - Symmetrical shapes have only a single median line of symmetry through which the pearl can be divided into two equal halves. Oval, button and drop shapes come under this category of pearl shapes.
3) Baroque - Baroque pearls have an irregular shape without a line of symmetry. Semi-baroque and baroque pearls fall under this category.
Posts by Lareef
The extremely rare quahog pearls, produced by the saltwater clam Venus mercenaria (Mercenaria mercenaria), whose natural home is the north Atlantic coastline from Canada's Gulf of Saint Lawrence to Florida and extending into the Gulf of Mexico, are also a class of non-nacreous pearls. The occurrence of gem-quality quahog pearls of the desired lilac to purple color is extremely rare, and believed to be around one in 2 million. Like the conch pearls and melo pearls, quahog pearls too exhibit a type of chatoyancy, that produces a shimmering effect and sometimes an "eye effect" that enhances the beauty of the pearl, surpassing the beauty of some nacreous pearls. Due to their extreme rarity only a few quahog pearls of the desired color and quality had appeared at public jewel auctions, and it may be difficult to set a value for any high-quality quahog pearl. This was the difficulty faced by Alan Golash, the jeweler from Newport, Rhode Island, who owned the Golash Quahog Pearl Brooch, incorporating as its centerpiece one of the finest and largest quahog pearls on record, the "Pearl of Venus," when he wanted to dispose of this rare and exquisite piece of antique jewelry, of 19th-century provenance. As there had been no precedent of valuing a high-quality quahog pearl before, pearl experts had quoted values ranging from $250,000 to $ 1 million for the pearl brooch. The value of $250,000 is the most conservative estimate for the value of this rare quahog pearl brooch, and seems to agree with prices realized with other high-quality non-nacreous pearls, such as conch pearls and melo pearls.
However, four purple quahog pearls weighing 13.0 carats, 12.0 carats, 7.0 carats and 3.5 carats and having dimensions respectively of 12 x9 mm, 12.5 x 9.2 mm, 11.2 x 8.5 mm and 9.0 x 7.0 mm, that was sold at the Bonhams Los Angeles auction on December 7 & 8, 2008, for $60,000 might give some indication of the value of the Golash Quahog Pearl Brooch. The 14 mm "Pearl of Venus" has a shade of lilac color, and shimmer, clearly superior to any one of these purple quahog pearls, apart from the fact,the pearl also shows a rare and unique "eye" effect. The combination of all these rare characteristics and the Victorian era provenance of the antique piece, undoubtedly enhances the value of the Golash Quahog Pearl Brooch.
Thumbnails below 1) four quahog pearls sold at Bonhams, Los Angeles auction and 2) the Alan Golash Quahog Pearl Brooch.
You are correct to some extent, but unfortunately the difference in the pricing of nacreous pearl incorporated jewelry and non-nacreous pearl incorporated jewelry, that runs into the hundreds of thousands of dollars for the former and tens of thousands of dollars for the latter, still remains, and will remain so in the foreseeable future, until the public perception and misconception of associating nacreous pearls with the misnomer "true pearls" and non-nacreous pearls with the misnomer " not true pearls" is removed forever.
However, at least for melo pearls there appears to be a renewal in interest and a corresponding appreciation of prices as recorded by a rare melo pearl of 224 carats (896 grains), the second largest melo pearl on record and the 9th to be sold at an auction, that appeared at a Christie's Dubai auction on October 27, 2010, which fetched a staggering US$722,500, a world record price for a melo pearl sold at an auction, 4 times the lower pre-sale estimate of US$ 180,000 and almost 3 times the upper pre-sale estimate of US$ 250,000, which was purchased by a Chinese private collector.
Melo pearls are another class of non-nacreous pearls, produced by one of the species of melo volutes, such as Melo aethiopica, Melo amphora, Melo broderipi, Melo georginae, and Melo melo. These pearls were largely unknown to the Western World,until as recently as 1993, the year when the New York based jeweler, Bengamin Zucker, with the help of his friend, Kenneth Scaratt of the GIA, identified 23 of these deep-orange fiery pearls, sent to him by a Swiss dealer, who had purchased them from Vietnam. Zucker, then headed a small team of gemologists, who visited Vietnam, to find out more about these pearls and the sea snails that produced them. The result of this research on Melo pearls, was published in a 1997 article in the Smithsonian Magazine, that gave a big boost to the popularity of these pearls.
As a result of this publicity, a single fiery-orange melo pearl registered a record price of US$ 488,311, at a Christie's auction in Hong Kong in November, 1999. This was followed by the record sale of another single fiery-orange melo pearl for US$ 277,272 at a Christie's Hong Kong auction in April 2000. The unprecedented prices recorded by these pearls led to a rapid increase in the harvesting of melo volutes,in Vietnam, Burma, Cambodia and Thailand, resulting in an increase in the production of melo pearls, and a corresponding decrease in their prices, from hundreds of thousands of dollars to tens of thousands of dollars.
Some of the recent auction results are given below :-
1) A creamy orange colored melo pearl, with dimensions of 20.0 x 19.5 mm and weight 57.25 carats, sold at Bonhams Los Angeles sale for US$ 16,800, on December 7 & 8, 2008.
2) Another bright orange melo pearl of dimensions 11.0 x 10.5 mm and weight 10.28 carats, sold for $7,800 at the same auction.
3) However, the highest price ever recorded by jewelry incorporating melo pearls, was registered at a Sotheby's auction in Hong Kong in 2008. A melo pearl jewelry suite, consisting of a necklace incorporating 14 melo pearls, a pair of earrings incorporating two melo pearls in each earring and a ring incorporating a single melo pearl, combined with jadeite and diamonds, sold for a staggering US$ 692,000.
The thumbnails below represent 1), 2), and 3) above.
Yes indeed Sunil ! you are right. Let me give you some examples of drop earrings that registered fantastic prices at recent auctions.
1) Pair of Antique Natural Pearl and Diamond Ear Pendants, that sold for US$ 217,000 at a Christie's Dubai auction on April 29, 2008.
2) Fine Pair of Natural Pearl and Diamond Ear Pendants, that sold for US$ 157,000 at the same Christie's Dubai auction on April 29, 2008.
3) Pair of Art Deco Natural Pearl and Diamond Pendant Earrings, that sold for US$ 165,176, at a Christie's Geneva auction on May 12, 2010.
4)Marie Mancini pearl and diamond ear pendants, that sold for US$ 253,000 at a Christie's New York auction in 1979.
The following thumbnails are 1), 2), 3), and 4) above.
The "Pearl of Allah" is no doubt the largest pearl in the world, but certainly not the most expensive.
Conch Pearls also known as "Pink Pearls," perhaps the only natural pearls with a pink body color, are another important class of non-nacreous pearls, that were very popular during the Belle Epoque period from 1901 to 1915. It was during this period that the famous piece of jewelry known as the "Queen Mary Conch Pearl Brooch" designed. However, after the production of cultured pearls by Mikimoto, the popularity of Conch pearls decreased. Recently, there has been a surge in popularity of Conch pearl incorporated jewelry, due to the effort of two individuals, the Geneva-based jewelry manufacturer, Georges Ruiz, and Susan Hendrickson, the marine archaeologist, paleontologist and professional diver, who has the largest collection of Conch pearls in the world. Some of the prices realized by conch pearl jewelry at recent auctions are as follows :-
1)A diamond and conch pearl pendant necklace sold for £3,750, above the pre-sale estimate of £3,000 to 3,500, at a Christie’s London auction on February 27, 2008.
2)Pair of stunning conch pearl and diamond drop earrings, sold at Sotheby’s London sale on July 22, 2008, for £20,000 above the pre-sale estimate of £10,000 to £15,000.
3)Diamond and conch pearl bird brooch sold at Sotheby’s auction, New York on Sept.25, 2008 for $15,000 above the pre-sale estimate of $5,000 - $7,000.
4)A conch pearl and diamond pendant necklace sold at a Christie’s auction in London on Dec.8, 2010 for $ 4710, above the pre-sale estimate of $3,700 to $3,900.
5)A conch pearl and diamond necklace sold for $45,200 at a Christie’s Hong Kong auction on May 31,2011, above the pre-sale estimate of $19,000 to $32,000.
6)A conch pearl, melo pearl and natural pearl pendant necklace sold for $54,886 at the same auction above, higher than the pre-sale estimate of $36,000 to $49,000.
The following thumbnails represent 2), 3), 4), 5) and 6) above :-
Out of all non-nacreous pearls the most renowned are the blister pearls, two of which created international headlines, the "Pearl of Allah" and the "Palawan Princess" the 1st and the 2nd largest non-nacreous blister pearls in the world, weighing 6.1 kg and 2.27 kg respectively and discovered from the giant clam, Tridacna gigas, off the coast of the island of Palawan, in the Philippines. Staggering estimates about the value of these two pearls, had been given by various authorities. However,the highest price ever recorded for the "Pearl of Allah" was US$ 200,000 in 1980, when the pearl was purchased by Peter Hoffmann and Victor Barbish, at the sale of the estate of the original owner of the pearl, Wilburn Cobb. Based on this, a modest pre-sale estimate of US$ 300,000 to 400,000 was placed on the "Palawan Princess" when it was put up for auction by Bonhams on December 6, 2009, at Los Angeles, but there were no takers. Such blister pearls of enormous size have a collectors value, but sadly failed to impress at public auctions. The first photograph attached below is that of the "Pearl of Allah" and the second, "Palawan Princess."
Conch Pearl is defined as a non-nacreous pearl consisting of calcium carbonate arranged concentrically in a crossed lamellar microarchitecture. This structural characteristic usually produces a flame-like surface pattern and porcelaneous sheen. Such pearls are produced by various gastropods including the Queen Conch (Strombus gigas), Horse Conch (Pleuroploca gigantea), and the Emperor Helmet (Cassis madagasgerensis). Also known as pink pearls.
Melo Pearl is defined as a natural non nacreous pearl found in one of the melo volutes, such as Melo aethiopica, Melo amphora, Melo broderipi, Melo georginae, and Melo melo.
Quahog Pearl, being a clam pearl is defined under clam pearl. The clam pearl is defined as a natural pearl from the hard-shell and giant clams, e.g., Mercenaria mercenaria (quahog) and Tridacna gigas (giant clam).
It is important to note that nowhere in the CIBJO Pearl Book, has the word "True Pearl" been used or defined. CIBJO does not recognize the term "True Pearl." Natural pearls are only classified as "Nacreous" and "Non-Nacreous." Non-Nacreous pearls are defined as natural pearls without a surface nacreous layer. eg. clam pearls, conch pearls, melo pearls, some pen pearls and scallop pearls. Hence it appears that the terms "true pearl" and "not a true pearl" are misnomers wrongfully applied by the common man and the pearl trade in general, to refer to "nacreous" and "non-nacreous" pearls respectively.
Yes, there is. The international body recognized worldwide is the "CIBJO - The World Jewelry Confederation," based in Milano, Italy, a non-profit confederation of national and international trade associations including commercial organisations involved in the jewellery supply chain, that sets the standards and guidelines in respect of all sectors of the jewelry industry, such as diamonds, colored gemstones, pearls, precious metals etc. The CIBJO records the accepted trade practices and nomenclature for the industry throughout the world, encouraging harmonization and promoting international co-operation within the jewelry industry. This is achieved by the setting up of committees and commissions for each sector of the industry, consisting of experts and representatives of the trade, in each relevant field, who collate the guidelines and nomenclature applicable to that field, which are then published as the CIBJO Blue Books.
The CIBJO Blue Books are a definitive set of standards for the grading, methodology and nomenclature for diamonds, coloured gemstones, pearls, precious metals, and since recently also for gemmological terminology and nomenclature. The CIBJO Blue Books were initially compiled, and since have been consistently updated, by a number of committees, comprised of representatives from trade organizations and laboratories in the diamond, coloured gemstone, cultured pearl, precious metals and jewellery industries. The standards represented a consensus derived from the broad expertise on the subject within these committees, and also from individuals outside the committees who had expressed an interest in participating in the development of the guidelines.
The CIBJO Pearl Commission is headed by Ken Scaratt, the Director of the GIA in Bangkok, who initially suggested the re-classification of conch pearls, melo melo pearls and quahog pearls with a flame structure as "true pearls." The Pearl Commission consisting of members of all stakeholders in the natural and cultured pearl industry, met as recently as November 9, 2011, in Hong Kong. Addressing this meeting, president of the Commission, Ken Scarrat, stated, the purpose of the meeting was "to glean sufficient and valid opinions to allow the CIBJO Pearl Book to stipulate how to use the unqualified word 'pearl' in various scenarios. Given the wide and varied use of the term “pearl” within the English language, inevitably discussions within CIBJO have generated differing opinions on its ‘proper’ usage. Therefore, my colleague Shigeru Akamatsu [Pearl Commission VP]and I felt that the Pearl Commission needed to broaden its consultation circle regarding this particular issue before a valid and lasting resolution could be reached.The CIBJO Pearl Commission and its Steering Committee are committed to the production of meaningful standards of nomenclature that describe natural and cultured pearls as well as pearl imitations or simulants. Evidence of this commitment is found within the pages of the current CIBJO Pearl Book, the contents of which reflect many discussions with industry professionals during CIBJO’s annual Congresses as well as occasional meetings and discussions in between. I am grateful that such an impressive array of attending industry experts deemed the issue important enough to devote their time to the highly productive discussions that took place at the meeting, as well as prior electronic and personal discussions with pearl industry members who were not able to be in Hong Kong." He concluded by saying that, he felt that sufficient discussion had taken place to allow for a workable resolution that would meet the needs of all elements of the industry as well as of the consumer. Following further discussions within the CIBJO Board of Directors, the resolution will be available within an updated version of the Pearl Book shortly.
Joan, the above discussion I hope answers your question.
Yes Mike, I agree with you on this point. Some conch pearls, melo-melo pearls and quahog pearls produce a flame-like shimmering effect known as "flame structure," a form of chatoyancy, whose spectacular effect sometimes surpasses the iridescent effect of some low grade nacreous pearls. This is one reason that has prompted some pearl experts, like Kenneth Scarrat, the director of GIA in Bangkok, and Susan Hendrickson, who owns the largest conch pearl collection in the world, to suggest that conch pearls, quahog pearls and other pearls that exhibit the "flame structure" be re-classified as "true pearls." The following photographs of a melo-melo pearl, Queen Mary conch pearl brooch, rare quahog pearl and Elizabeth Taylor's La Peregrina pearl that sold recently for $11 million, gives a comparison of the beauty of these non-nacreous pearls with a true nacreous pearl :-
From a biological point of view all shelled mollusks, such as oysters, mussels, clams, conchs, scallops, melo-melo shellfish etc. are capable of producing pearls. However, these pearls can be classified into two types :- Nacreous and Non-Nacreous. Nacreous pearls are composed of a substance called "nacre" a complex organic-inorganic material. The organic part known as conchiolin, is a sceleroprotein, while the inorganic part made of hexagonal plates of aragonite or calcite, are actually crystalline forms of Calcium Carbonate. The tiny aragonite plates are arranged in parallel layers, separated by the organic matrix conchiolin. When light falls on the nacre, the tiny aragonite platelets that has a width comparable to the wave length of visible light, cause the scattering of light, producing the effect known as iridescence. From a gemological point of view only nacreous pearls that show the luster and iridescence caused by "nacre" are considered as "true pearls," and such pearls are produced only by saltwater oysters and freshwater mussels.
Pearls produced by clams, conches, scallops, melo-melo shellfish etc. are non-nacreous pearls, and gemologically not considered to be "true pearls." In non-nacreous pearls too a nacre-like substance consisting of aragonite/calcite and conchiolin is produced, but the aragonite/calcite is deposited as needles, which does not scatter light as the short hexagonal platelets. Hence the nacre-like substance in non-nacreous pearls does not have the luster and iridescence of nacreous pearls. The luster of non-nacreous pearls is a low and subdued luster, with a sheen similar to that of porcelain, sometimes referred to as "porcellaneous." Hence, pearls produced by conchs, melo-melo sea snails and quahog clams are technically not "true pearls" even though the special "chatoyant effect" shown by these pearls sometimes surpass the beauty of iridescent pearls.
From a biological point of view all shelled mollusks, such as oysters, mussels, clams, conchs, scallops, melo-melo shellfish etc. are capable of producing pearls. However, these pearls can be classified into two types :- Nacreous and Non-Nacreous. Nacreous pearls are composed of a substance called "nacre" a complex organic-inorganic material. The organic part known as conchiolin, is a sceleroprotein, while the inorganic part made of hexagonal plates of aragonite or calcite, are actually crystalline forms of Calcium Carbonate.
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