Pearl

 

REVEALING THE UNKNOWN TRUTH ABOUT OF PEARLS

We cannot discuss pearls without mentioning their genesis. So, here we go! At the beginning of this pearl jewelry write-up, I will focus on the most critical parameters that can be used to describe and evaluate natural Akoya pearls ( Pinctada fucata - oyster known in Japan as Pinctada martensii ) and cultured P. maxima pearls ( Australian South Sea pearl oyster ) in terms of physical dimensions and actual quality. In addition, I will reveal general information about many other types of natural and cultured pearls. Still, I will overlook the dubious and unprofessional information spread on social networks by unapproachable and professionally opaque sellers.

Considering my experience with pearl jewelry, I will not deal with astrological, magical descriptions and health effects like some unresponsive sellers. Still, I will only adhere to the strict professional criteria set by the standards of The World Jewellery Confederation (Confédération International de la Bijouterie, Joaillerie, Orfèvrerie des Diamants, Perles et Pierres), which is the primary international jewelry confederation representing the interests of all individuals and companies earning their livelihoods from manufacturing, and trade of these products. It is the oldest such organization, having originally been established in 1926.

Taking into account what was emphasized above, I will concentrate from the beginning to unfold the issue of pearl classification. Generally, there are only two types of pearls: 1. NATURAL PEARLS 2. CULTURED PEARLS. While all other pearls are imitations, they are artificially processed using plastic materials with very sophisticated coloring. They are not produced within the body of mollusks but are manufactured products made in factories.

1. NATURAL PEARLS

Without human intervention, natural pearl formations are secreted in the interior of mollusks and within a naturally formed pearl sac. They are composed of a complex scleroprotein called conchiolin and calcium carbonate in the form of aragonite or calcite arranged in concentric layers. Natural pearls may be nacreous or non-nacreous. Natural pearls are divided into two categories:

a.Saltwater Pearls

They are produced by various marine mollusks, including pearl oysters, common edible oysters, snails (gastropods), clams, and scallops.

b.Freshwater Pearls

Various species of freshwater mollusks in rivers and lakes produce them.

2. CULTURED PEARLS

Cultured pearls are formed in the interior of living mollusks within a cultured pearl sac with human intervention and various conditions depending upon the mollusk and the goals. Cultured pearls may be nacreous or non-nacreous. Cultured Pearls are divided into two categories:

a.Saltwater Cultured Pearls

They are produced predominantly by three species of Pearl Oysters.

b.Freshwater Cultured Pearls

Clams and mussels produce it in freshwater lakes and rivers.

Within these mentioned categories, two more included:

3. ORIENTAL PEARLS

"Oriental Pearl" is traditionally used for natural saltwater pearls from the Orient (broadly including Asia and the Far East). These pearls were considered the most beautiful of all pearls and had the most desirable shapes and sizes. They had a unique appearance that combined a deep luster and subtle colors visible through their translucent "skins" – this feature is described as a pearl's "Orient."

4. IMITATION OF PEARLS

Imitations of pearls are products that only simulate the appearance of natural or cultured pearls. They are not produced within the body of mollusks but are manufactured products made in factories.

Many mollusks can produce pearls, but only particular species can produce pearls of a quality suitable for use in Jewellery. The appearance of nacre is the biogenic material of nacreous natural and cultured pearls. Nacre comprises layers of microscopic aragonite platelets (calcium carbonate) bound together by an exemplary network of a complex scleroprotein called conchiolin. This characteristic structure produces optical effects (Orient, overtone) from within the natural pearl or cultured pearl. Nacre is secreted from the mantle of pearl oysters, some other bivalves, e.g., freshwater mussels, and some gastropods.

In addition to the two sea shells that were mentioned at the beginning of the article, pearls are also produced from these other types as follows:

Philippine South Sea pearl oyster, Asian South Sea pearl oyster (Indonesia, Myanmar and Vietnam), Tahitian Black-lipped pearl oyster (Pinctada margaritifera cummingi, Central Pacific Ocean and French Polynesia), Fijian Pearl Oyster ( Pinctada margaritifera typica, Western Pacific Ocean), Gulf and/or Ceylon pearl oyster ( Indian Ocean from Sri Lanka ( Pinctada radiata, Ceylon to Persian/Arabian Gulf), Atlantic pearl oyster ( Pinctada imbricata, Western Atlantic from Bermuda and Florida to South America ),

Mexican black Lipped / La Paz pearl oyster ( Pinctada mazatlanica, natural habitat is the Gulf of California, Mexico to Peru ), Pipi pearl oyster ( Pinctada maculata, Pacific Ocean particularly near French Polynesia and the Cook Islands ), Black-winged pearl oyster ( Pteria penguin, Natural habitat is from Amami Island (Japan) to Pacific Ocean and Indian Ocean, known as mabe gai in Japan) and Rainbow lipped pearl oyster ( Pteria sterna, ranges naturally in the eastern Pacific from Baja California to Peru ).

All natural pearls and cultured Pearls are classified according to five characteristics known as The Five Virtues:

Lustre, Color, Surface, Shape and Size.

LUSTRE

Luster is the appearance or the brilliance of the pearl in reflected light. It is judged by the sharpness of the reflection of a light source seen on the surface of the pearl. Lustre may range from dull to very bright.

Natural Lustre: Excellent (Reflections are bright, sharp, and distinct), Good ( Reflections are brilliant, but not sharp ), Fair (Reflections are weak, hazy, and blurred ), Dull ( Reflections are dim and diffused, or no reflection is apparent )

COLOUR

All colors may be with or without overtone and Orient  golden to white with cream variations:

Golden, Yellow, Light Yellow, Cream, Light Cream, White, Pinkish Cream, Light Pinkish Cream, Pinkish White, Greenish Yellow, Light Greenish Yellow, Silver White, Brownish Yellow, Light Brownish Yellow, Brownish Cream, Purplish Cream, Light Purplish Cream.

Grey's and other color variants: Black, Dark Grey, Silver, Light Silver, Purplish Grey, Purplish Silver, Pinkish, Pinkish Silver, Purple, Blue, Brown, Light Brown, Red, and Pink.

SURFACE

Clean: pearls are blemish-free containing minute surface characteristics that are very difficult to see by trained observers with the naked eye.

Lightly blemished (Slightly spotted): pearl shows minor surface irregularities when examined by a trained observer.

Moderately blemished (Moderately spotted): pearl shows noticeable surface characteristics. Heavily blemished (Heavily spotted): pearls show apparent surface irregularities that might affect durability.

Note: Visible flaws away from drill holes affect surface appearance grades more than near the spots.

Pearl Blemishes:

• Bumps and welts.

• Discolorations: spotty areas often caused by concentrations of conchiolin.

• Chips, Holes, and Patches of Missing Nacre.

• Wrinkles: an irregular ridge of the crease on the surface.

• Pits and pinpoints.

• Dimples.

• Dull Spot: area of very low luster due to variations in nacre quality or contact with chemicals.

• Cracks

• Scratches.

Indentations.

SHAPE

Externally they shall be round to the eyes - they should roll easily across a flat surface in a straight or nearly straight line; any difference in dimensions shall be =/<5% of the minimum size.

Partial-round

Externally they shall look off-round (nearly round) to the eyes - when rolled across a flat surface, they will almost travel in a straight line, and the dimension difference shall be >5% of the minimum dimension.

Button

Externally one side is flat or near flat when viewed in profile and may be low or high-domed. Should be able to stand motionless when the flat or nearly flat side is down on a flat surface.

Oval

Externally they must be round/rounded in cross-section (i.e., down their length) and usually elongated. However, shorter examples can also be found as it is difficult to classify the shorter ones under any other shapes.

Drop

Externally they must be round/rounded in cross-section (i.e., down their length) and usually elongated with one end narrower than the other. However, shorter examples can also be found as it is difficult to classify the shorter ones under different shapes.

Baroque

Pearls that are asymmetrical to a lesser or greater degree; are irregularly in shape.

Doubled

Two pearls that have grown together as one.

Clustered

Several pearls have grown together as one.

Blister pearl

A natural pearl that has perforated the mantle of the mollusk and has naturally adhered, through layers of nacreous or non-nacreous secretions applied by the mollusk, to the inner wall of the shell. The subsequently formed layers of nacreous or non-nacreous material are continuous with those of the inner wall of the shell. They are round or irregular in shape.Round, Partial Round, Button, Partial button, Circlé button, Oval, Partial oval, Partial oval, Drop, Double drop, Circlé drop, Doubled, Clustered, Baroque, Partial baroque.

SIZE

Graduated sieves sort the natural pearls into different sizes, from the large to the most miniature pearls. Akoya complex pearls are often sold by Chaw (volume) and Methgal.

The international norm for recording the weight of a natural pearl is the "pearl grain" - 1 pearl grain = 0.25 ct.

While the size of cultured pearls is measured in millimeters across the widest horizontal axis or, for more precise measurement, across the broadest horizontal axis, the narrowest horizontal axis, and the longest vertical axis.

The weight of cultured pearls is measured in momme or carats. 1 momme = 3.75 grams

1 carat = 0.20 grams

Weight/price calculation

"Once-the-weight" natural pearls are not priced at 'so much per grain' but by an elaborate method using a base price referred to as the 'unit base price.' The value is arrived at by simply squaring the weight of an individual pearl in grains and multiplying the result by the base (unit) price.

➣ grains x grains (unit, e.g., one shilling) -

Measurements

Pearl measurements are generally recorded in millimeters, occasionally in centimeters. Whichever is used, the numerical values are given to only two places of decimal, e.g., 22.33 mm or cm.

In each instance, the Minimum and maximum diameters are recorded along with the entire length: the full length and Minimum and maximum diameter.

Natural and cultured pearls may have been treated to improve the appearance of color and luster.

UNTREATED PEARLS

Pearls with natural color and luster.

Fine quality pearls have attractive color and excellent luster from the moment they are taken from the mother oyster. Such pearls require no luster or color enhancement before setting as Jewellery.

Fine quality pearls with long-lasting natural beauty that require no enhancement are exceedingly rare and highly prized, reflected in their value.

Note that regular buffing or polishing is not considered a treatment.

TREATED PEARLS

Pearls that have been subjected to treatments to remove blemishes, change the pearl's color, or improve the pearl's luster to achieve the desired appearance.

Various treatments are commonly applied to lower-quality pearls to improve their appearance and make them suitable for Jewellery, creating a more affordable and accessible product for a broader market.

Techniques involving light chemical treatments may improve the appearance of lower-quality pearls. The improved luster from such treatments generally fades over time, but this does not damage the pearl's structure. Heavy chemical treatments may adversely affect the pearl's system and can sometimes impart a coarse and chalky look and feel over time.

Some treatments are difficult to detect, and consumers should request a natural color and luster guarantee for high-value pearls.

Accidentally or unintentionally produced saltwater cultured pearls without a solid bead at their center are called non-bead cultured pearls. Some are known as "Keshi cultured pearls" from the Japanese word for "poppy seed," indicating their sizes as initially conceived. However, larger non-bead cultured pearls are referred to today as "Keshi." TodKeshishi cultured pearls generally range in size from sometimes <1 mm – 16 mm but are occasionally found in larger sizes which are considered very rare.

For the sake of correct information about pearl jewelry and transparency in front of ValentinsJewellery customers, it was more than necessary to reveal the unknown truths, in terms of Physico-chemical, manufacturing, commercial and aesthetic parameters, with a desire that the opinion wide to be informed correctly and fairly.

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