Round, smooth, precisely measured and orderly, akoya pearls have the classic look that many find indispensible with business and formal attire. These ocean pearls, cultivated exclusively in-body in small Pinctada species that live in temperate waters, remained what most people meant by pearls for close to half a century. Japan exported the technology made famous by K. Mikimoto to Australia, making Southsea pearl cultivation using much larger tropical Pinctada species possible. Later, it was also brought to China, where ocean pearl cultivation developed much less rapidly than freshwater cultivation.
Read more in detail about provenance.
The valuation of akoya pearls is based on degree of perfection and size. The shape is mainly prized for faithful adherence to the perfectly spherical tool-made shell bead nucleus (generally freshwater mussel shell is used, preferably from USA). Perfection is of course elusive, and where natural processes are relied on for production, it is not a reasonable requirement.
The degree of perfection desired from akoya pearls can easily be obtained in imitation pearls made with modern machinery. Some manufacturers try, albeit with little success, to add convincing flaws to their simulants. Pearl imitations are easily detected because they have a paint surface, and therefore are rarely a concern for pearl buyers. However, an oversimplification of the concept of quality that disregards nacre thickness has caused the proliferation of akoya pearls with extremely thin coating. These could not satisfy the expectations of many customers, most of whom assumed they were buying durable gems.
Read more in detail nacre thickness.
Akoya pearls’ color is widely expected to be white or white-pink, the least likely to occur naturally in shells that are creamy-yellow to greenish. The most unnatural color that bleaching can acheive without losing too much lustre is valued highest. Relatively light color has long been a priority in breeding pearl oysters, so few are yellow enough to satisfy the recent demand for “golden” color. As a result, previously unimaginable yellow dye came into widespread use nearly a decade ago.
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A perfectionist approach, based on rejection of many of akoya pearls’ natural characteristics, thus defined the popular ideal. It probably pleased jewelers familiar with gemstone grading, and helped cultured pearls gain their place alongside the noble minerals. Giving priority to such factors as flawless surface at any but exalted price points is however misguided. Not only does it encourage consumers to buy a pretense of quality, it causes pretend quality to become the norm.
Now under pressure from both China freshwater and southsea competition, akoya pearls have become excellent value for those who approach the product realistically. This requires some understanding of the nature of the product, and of the tradeoffs inherent in each valuation factor. Individual taste does vary, at least in terms of priorities among desired factors. Guided by market knowledge, those preferences should determine pearl choices, especially regarding quality and color.
Large pearls tend to have more irregularities, because they need more nacre thickness than small ones do in order to avoid the nucleus showing through. Always inspect pearls by rotating all or most of a strand… this not only shows the irregularities on all sides, but a reflection from within the shell bead nucleus of the pearl (moonstone effect) occurs when the coating is very thin. Such pearls should be excluded from surface quality comparisons because their nacre is too thin to be durable.
Read more in detail nacre thickness.