To Assist the Goddess: the Cultured Pearl Quiz

Answer: Carolus Linnaeus

Linnaeus hoped to sell his patented process for a fortune and live in comfort the rest of his life. Unhappily for him, his prospective purchaser King Adolf Frederick of Sweden had more pressing concerns. Linnaeus had to settle for a title of nobility for his invention. Of course, his binomial classification system of living things proved so useful and flexible that it is still used today. He didn't get rich, but he did achieve scientific immortality.

Pearls cultured by Linnaeus are kept in the collection of the Linnean Society of London. They can be seen illustrated in the book "Pearls: A Natural History" by Neil H. Landman et al.

Answer: The insertion of tissue from another mollusk to stimulate production of nacre

Pearls are cultured in fresh river and lake water as well as the ocean, although pollution is a threat to them in any environment. Nuclei have been shaped into many forms, and are not used at all in some techniques. Several species of mollusk are important in commercial pearl production. The genus Ostraceae are not among them; they are popular as food but produce lusterless and unattractive pearls.

Answer: A variable proportion of a cultured pearl's weight represents the nonprecious nucleus

Specific gravity ranges have been described for both ocean and freshwater pearls. Although not originally a metric unit, the carat has been standardized at 200 milligrams. The weight of the nucleus depends on its size, while the amount of nacre can vary widely.

Cultured pearls as a bulk commodity are sometimes sold by weight, using the Japanese unit "momme." However, this system is not applicable to single pearls or to pieces of pearl jewelry.

Answer: Almost all are grown in bivalve or double-shelled mollusks.

While natural pearls formed by some univalves (snails) such as conch or abalone can be very rare and beautiful gems, efforts to culture these pearls have had only limited success. Some blister pearls suitable for assembling into jewels have been cultured in the abalone, but as of 2003 production is very modest in size and not of commercial importance.

Answer: A distinct boundary between nucleus and nacre layer indicates a cultured pearl.

Prior to today's use of X-rays, a test was used which involved threading a tiny endoscope with 2 mirrors through the hole in a pearl and reflecting a strong light beam off them. This could test only one pearl at a time and was not helpful for assessing undrilled pearls.

Answer: An irregular empty space in the center of the pearl means it was cultured.

Although natural pearls usually form around a soft-tissued parasite, these tiny organisms will not leave large, prominent spaces visible on X-ray.

Answer: Cultured pearls have no concentric growth rings

It is very difficult to tell a cultured pearl from a natural one without X-ray equipment. X-rays shows that the structure of the pearl follows the shape of the bead at its centre rather than forming the concentric rings of the natural pearl.

Answer: A pearl blister or hollow dome, cut free from its shell and cemented onto a mother-of pearl mounting

Mabe, often garnished with an accent mark, is pronounced "mah-BAY" by producers and sellers of the product.

Answer: Chinese freshwater cultured pearls

The first Chinese cultured pearls to be imported were elongated and deeply wrinkled, reminding buyers of the breakfast cereal. As culturing techniques became more precise, rounded smoother ones were produced which were shaped like potatoes or like plump kernels of corn on the cob.

Answer: He initially resisted labeling his pearls "cultured" because they were chemically identical to natural pearls.

Mikimoto was proud of his pearls and specifically labeled them as cultured. He successfully demanded that the higher import duties applying to gems were placed on them, to indicate their genuine status. It was largely due to his marketing that the cultured pearl made pearl jewelry accessible to most women. It was not long before cultured pearls supplanted natural ones almost entirely.

Mikimoto deserves a whole quiz centered on his accomplishments, and perhaps will someday have one.

Answer: The species used to culture Japanese saltwater pearls.

I don't know what pearl farmers call an unsatisfactory oyster, but they must have a name for it!

Answer: False

The FTC stands by its original rules: the terms "real", "genuine", and "natural" may be used to describe natural pearls only, unless "cultured" is placed in the item's description in letters the same size and prominence as the rest of the title.

Answer: Pearls from oysters that have rejected their implanted nuclei and instead produced non-nucleated baroque pearls.

Although exceptionally lustrous, keishi are less desirable than spherical pearls. Their unique shapes (and their more reasonable prices) have made them popular with buyers and sellers alike. Many collectors consider them to be natural pearls formed by cultivated oysters. As such, they are acceptable to Muslim buyers.

Answer: An organic substance secreted by the oyster to cover its pearl nucleus; alternating layers of nacre and conchiolin permit pearls to grow in size.

This substance is secreted by all pearl mollusks and serves the function of stimulating further nacre production. The name is derived from the Latin word for shell.

Answer: South sea pearls

These include some of the most impressive and expensive pearls available. Colors range from silver white to creamy, rosy or golden tones.

Answer: Naturally dark-colored or black nacre

Tahitian pearls range from silvery gray to near-black. Their color is due to natural pigment from the oyster itself; no artificial enhancement is allowed in Tahiti.

Answer: The oyster "Strombus gigas" which is native to the region

The South Seas pearls come from the "Pinctada maxima" and "Pinctada margaritifera" species. "Strombus gigas" is the queen conch.

Answer: North American freshwater mussels used for cultured pearl nuclei, found in Mississippi and Tennessee rivers

The high quality of nacre lining these shells made them highly prized for pearl buttons as well as pearl nuclei, and demonstrated their potential as hosts for cultured pearls.

Answer: True

John Latendresse began experimenting with processes for culturing American freshwater pearls in the early 1960s and eventually developed the American Pearl Company, which has become famous for its superb products. Latendresse was passionately devoted to pearls, and his efforts are credited with saving several species of freshwater mussels from extinction.

His outstanding personal pearl collection can be seen in the Smithsonian Institution. His family continues to operate and expand the company today. John Latendresse is worthy of an entire quiz over his life's work, and may someday have one.

Answer: Technique of culturing

Culturing technique can, however, have a major impact on price. Chinese freshwater cultured pearls, for example, can achieve superb quality and remain relatively inexpensive. This happy situation is possible because the mollusks used are both large and prolific. They are able to support many pearls simultaneously.