Conch pearls, Quahog pearls and Melo Melo 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.

  • 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.


    http://www.internetstones.com/…h-the-pearl-of-venus.html

  • 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 :-

  • Wow !!! The non-nacreous melo-melo pearl, conch pearl and the purple quahog pearl look stunningly beautiful, in comparison with the La Peregrina, but sadly do not come anywhere near the whopping $11 million fetched by the latter, with a 500-year history and provenance.

  • 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.

  • 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.

  • 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 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 :-

  • Wow ! As you said, the conch pearl and diamond drop earrings look stunningly beautiful !!! Never seen anything like that before. Little wonder the pair sold for £5,000 more than the upper pre-sale estimate of £15,000.

  • 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.