Pearls of wisdom: Unravelling the complex world of appraising pearls

December 1, 2015

By Gina D’Onofrio

Signed Carlo Giuliano gold Etruscan revival necklace with cave pearls.

Pearls have been treasured for centuries as a symbol of wealth and nobility. Yet, they are no longer reserved for the privileged few. Today, we can all enjoy pearls of infinite variety and at any price.

Keeping up with the abundance of choice is the appraiser’s challenge. When we study pearl identification and grading, the primary focus is on natural, cultured saltwater, and freshwater pearls. Recognizing the variety can be difficult, but determining their value can be just as daunting. This is not a guide to pearl grading, however. If you are a practicing appraiser, we can safely assume you are a gemmologist who has studied pearl grading. Right? If not, I suggest you take a pearl grading class from a reputable gemmological school and consult some of the references listed at the end of this article.

A look back

Fortunate appraisers may encounter rare species, such as the conch pearl shown here, which has its own grading criteria and may require consultation with an expert who is familiar with this particular gem.

A discussion on pearl appraising cannot begin without mentioning the radical changes in supply and demand, starting with the introduction of the spherical cultured pearl in Japan by Kokichi Mikimoto in the early 20th century. More affordable than their natural counterparts, cultured pearls became a huge success, dominating the pearl industry until the 1960s. Freshwater Biwa pearls from Japan rode the next wave of popularity in the 1970s. Irregular ‘rice krispie’ Chinese freshwater pearls, cultured South Sea, and Tahitian pearls came to the fore in the ’80s, followed by larger, smooth-skinned freshwater ‘potato pearls.’ The 2000s were all about a myriad of new Chinese freshwater and Akoya pearl varieties.

There have been enormous developments in demand, perliculture, and supply, resulting in roller coaster price fluctuations. This can place an appraiser in some tricky situations. For example, how do you tell your client her 20-year-old cultured South Sea pearl strand has dropped in value… by less than half?! You could explain the increased number of pearl farms, subsequent oversupply, and competition has driven down the price. An alternative, though, may be to focus on the upside, which is her insurance premium will be greatly reduced.

Natural pearls have enjoyed renewed interest and a huge leap in value over the last decade. If you have a piece pre-dating 1900, chances are the pearls are natural and significantly more valuable than cultured (assuming they were not replaced at a later date). Recommend your client submit the pearls to a lab for advanced testing. This will determine whether the pearls are cultured or natural, as well as the species.

Also, when inspecting older pearl necklaces, particularly graduated strands, take the time to study the smaller gems. There was a time in the early- to mid-20th century when cultured pearls where added to lengthen shorter, antique, natural pearl strands. Unfortunately, testing can be prohibitive, so deciding to submit mixed strands to a lab is a judgment call for you and a gamble for your client. In addition, I do not recommend employing the services of your local radiologist, since they lack the skill and industry-specific equipment to properly X-ray the pearls and, more importantly, interpret the results. A word about old pearl laboratory reports: as with coloured gemstones, there have been new developments in pearl testing that may result in your conclusions differing from the report’s. For example, the first DNA test for pearls was introduced in 2013 for the three major pearl-producing oyster species: Pinctada margaritifera, Pinctada maxima, and Pinctada radiata. With that in mind, an updated report may be worthwhile for potentially valuable pearls. 

China takes the lead

The rapid development of Chinese perliculture has greatly impacted the international pearl market. Recent Chinese pearl exports are in the range of 1000 to 1500 tons per year compared to Japan’s eight tons per year. Chinese freshwater cultured pearl varieties include tissue-nucleated, bead-nucleated in-mantle, and bead-nucleated in-body spherical, baroque, and fancy shapes, all of which are available in natural and treated colours.

Concurrently, there is a limited supply of finer-quality Chinese cultured freshwater and Akoya pearls (0.5 per cent of its annual export); their increased prices may overlap that of South Sea and Tahitian pearls. There seem to be new techniques in pearl culture and treatments every year, which impact the pearl supply chain and value. For example, the strand of hollow, Chinese freshwater ‘souffle’ pearls your client purchased three years ago may be extremely difficult to replace today, as the labour-intensive method used to produce them is no longer cost-effective and production is limited. When appraising these pearls, your choice may be to replace them with new old stock or an entirely different freshwater pearl strand of comparable quality and desirability. Make sure your reasoning and method of replacement are clearly described next to your value conclusion.

It is difficult to discuss Chinese freshwater pearls without mentioning Edison pearls. Introduced in 2012, these in-body, bead-nucleated freshwater pearls have become the darling of the pearl industry. Betty Sue King of King’s Ransom Pearls offered the following description: “The spectrum of peach, pink, rose, lavender, and metallic finishes simply dazzle the eye and work their magic. The best are the classic round shape due to similar nucleation techniques used for South Sea cultured pearls. Pricing is primarily determined by quality of nacre, symmetry of shape, surface, colour, and size.”

Combined with an oversupply of commercial qualities, China’s introduction of new varieties has steered other pearl-producing countries in new directions. For example, Japan and Vietnam are focused on producing ‘classic’ Akoya pearls of exceptional quality, which they believe cannot be matched by Chinese Akoyas. As a result, consumers benefit from a greater supply of these pearls, making it easier to find replacements for grandma’s fine mid-century cultured pearls with a thicker nacre. The same may be said for cultured South Sea and Tahitian pearls. The commercial end of the market is saturated with these varieties. Farmers are focused on producing pearls of higher quality with a thicker nacre to set themselves apart from the competition and this is sure to have an impact on price.

Origin matters

Much like Burmese ruby and Kashmir sapphire, some pearls’ country of origin may significantly impact its value. Case in point: Japanese Kasumi pearls from Lake Kasumigaura. These gems are cultured and harvested by a very small group of pearl farmers and trade at a significant premium over their Chinese freshwater counterparts. Currently, the entire harvest of Lake Kasumi pearls is less than 33 lbs (15 kilos) per year. Unfortunately, Chinese freshwater in-body pearls are being misrepresented as Japanese Kasumi pearls, leading to much confusion in the trade and among consumers. “Japanese Kasumi pearls command on average 10 times the price,” says Sarah Canizzaro of importer Kojima Pearl Co., in San Rafael, Calif. Provenance is a major factor appraisers must consider when valuing these pearls. Her advice is to obtain copies of the client’s purchase receipts with dates wherever possible.

You may encounter other cases of mistaken identity affecting value, such as

How can you avoid making costly errors? First, meet the suppliers. Many of them specialize in certain varieties, so get to know who sells what. Find out where they exhibit. If you cannot attend the major trade shows, you may be able to visit them at a regional gem show closer to home. Second, stay current to the latest trends, developments in perliculture, and treatments. It is essential appraisers understand which colours occur naturally and which do not and why. Become familiar with industry jargon and trade names, such as ‘fireball,’ ‘coin,’ and ‘petal.’ They’re incorrect from a gemmological point of view, but allow you to conduct market research and communicate effectively with pearl vendors.

Remember, pearl prices are a moving target, so use price guides in conjunction with your market research. Attend gemmological conferences, read trade journals, and participate in online appraisal and pearl forums. I have listed some excellent resources at the end of this article.

Fortunate appraisers may encounter some of the rare species, such as conch pearl, quahog, abalone, melo melo, or cave pearl (not a typo). Look carefully and you will find most of these at the Tucson gem shows or your natural history museum. I was thrilled to see a Victorian gold necklace by Carlo Giuliano set with a fringe of cave pearls at Heritage Auctions. Each species is exotic and unique, with its own set of grading criteria that go far beyond the scope of this article. Suffice to say, if you encounter any of these pearls, consult an expert.

My hope is that by reading this article, appraisers will be willing to step outside their comfort zone to discover more about these extraordinary gems. The leading pearl suppliers are a small community who are extremely knowledgeable and passionate about what they do. I encourage you to meet them, attend lectures, and read the references included here. Then share this information with your fellow appraisers. I’m sure they will reciprocate and together you can elevate the standard of this wonderful profession.

References and resources

1) Pearl Guide Forum, a source of pearl information (

2) Kojima Pearl blog by Sarah Canizzaro (http://www.kojimaӬ

3) Gemguide, a resource for pricing gems (https://gemӬ

4) Accredited Gemologists Association (AGA) offers twice yearly lectures on the latest developments in gemmology (

5) Pearls by Elisabeth Strack, a seminal work on the science and history of pearls.

6) Margaritalogia by Elisabeth Strack, an in-depth newsletter on developments in the world of pearls (

7) Abstracts on pearl lectures from AGA’s 2011 conference (

Gina5C0A0497Ret2[3]Gina D’Onofrio has provided gemmological and jewellery appraisal services since 1992. She is an accredited senior appraiser, master gemmologist appraiser (American Society of Appraisers) and certified senior member of National Association of Jewelry Appraisers. D’Onofrio is co-instructor for the American Society of Appraiser’s GJ-202 appraisal report writing for insurance coverage class. She may be contacted via e-mail at[4].

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