The formation of a pearl occurs when a mollusk is exposed to a natural irritant that causes it to secrete alternating layers of material called conchiolin and nacre. These materials are not intended to create a beautiful jewelry adornment, but actually to coat the invading irritant and make its presence less bothersome to the host mollusk. Today, most available pearls are cultured pearls wherein a foreign object is purposely placed inside the body of the oyster in order to stimulate the secretion of the conchiolin and nacre. Unlike diamonds or gemstones, pearls are first and foremost classified by origin before they are graded by shape, size, color, luster, clarity, and nacre thickness. Grading of a pearl is generally relative to the best attainable pearl for the particular type or origin. Here GGS helps to explain the various attributes to look for when choosing quality pearls.

SIZE
Of course, a pearl may only grow as large as the space that is available to it within its host mollusk. Consequently, it is a worthwhile investment for a pearl farmer to take time and care in raising the mollusk before nucleating it with a bead or tissue. Due to the extra care that must be taken to ensure a larger pearl, size is a significant factor when evaluating a pearls worth.

SHAPE
The shape of a pearl refers to its overall symmetry or roundness. Perfectly round and symmetrical pearls are the most rare and thus most highly valued type of pearl shape. Even for the Akoya pearls whose origin begins with a round bead, movement of the water and muscle action of the host mollusk more often than not cause the pearl to take an asymmetrical shape. Pearls are available in other shapes as well, but these are priced on a different scale than the perfectly round pearls. Pearl shapes are cataloged as follows:

• Round: A round pearl may be defined as Round-in-all, Mostly Round, Slightly Off-Round and Off-Round
• Drop: A drop pearl is teardrop or pear shaped. Naturally, the more symmetrical the pearl is, the higher the quality.
• Barrel: This pearl shape is more or less cylindrical, with blunt ends.
• Ringed: Ringed pearls develop when the host oyster had been turned over multiple times in one place, causing attractive grooves to develop on the pearl.

NACRE THICKNESS
Gemologists and professionals agree that nacre is the single most important factor in the overall beauty and durability of a pearl. Nacre should be thick enough to mask the bead hidden within; if it is cracked or peeling, or displays chalky seeming patches on the exterior than the pearl is of a considerably lower quality. A pearl with thin nacre has been in the water for a briefer time than a pearl with a thick nacre, and this thin surface will undoubtedly experience damage by normal wear. Always seek out pearls with a medium nacre or more, which is defined as at least 0.35 mm thick.

LUSTER
The luster of a pearl defines the reflectivity or brightness of the pearl. Pearls of the highest quality have a strong metallic luster, whereas slightly lower quality but still fine pearls exhibit a sub-metallic luster while still reflecting objects in sharp relief on the surface. The lowest quality pearls exhibit low luster, and display very little if any reflectivity at all.

COLOR
Pearl color may be categorized by three defining characteristics:

• Body color: The body color of a pearl is the base color observable near the pearl’s outer edges. White or silver-white are the more preferred body colors; cream and gray body colors are less desirable when it comes to strictly defining quality. However, color preference for your pearls is a personal decision and may also be selected to complement the skin tone of the wearer.
• Overtone: On any pearl, one or more colors may overlay the body color. The outermost observable color layer is the overtone. The overtone is best observed by directing your attention just off the dome of the pearl. The preferred overtones to seek out are pink, whereas greens are less desirable.
• Orient: A pearl’s orient refers to the iridescent play of colors which seems to move along the surface. The orient is a rare component of a pearl’s value, and is more often seen on irregular surfaces.

SURFACE BLEMISHES OR TEXTURE
A pearl’s surface blemishes or texture indicate blemishes or spotting on the surface of the pearl. These imperfections are tagged and graded by their size, type, number, location and visibility.

MATCHING
Matching is a term mostly used in reference to pairs or strands of pearls, and addresses the uniformity of luster, shape, color and overall uniformity of the group. If the colors of the strand have been purposely variegated, than the matching will indicate the success of the combination. In a uniform strand, there should exist no noticeable difference between pearls that are adjacent to one another. Ideally, the order of pearls in a strand will have been systematically chosen based on perfect matching. An uneven blend of colors, shapes, or luster in a strand will decrease the overall value of the strand.

PEARL CARE
GGS always encourages you to protect your pearls from chemicals and abrasion. Pearls are very soft by nature, and are easily scratched or damaged by harsh contact with other jewelry. Pearls are easily scratched by careless cleaning due to harsh dust particles that land on your pearl, or even on the cloth you chose to clean your pearls. GGS recommends that you keep pearls in their own soft case or bag, and wait to put them on until all your products and personal grooming steps have been applied and completed. After wearing pearls against your skin, wipe down gently with a very soft, damp cloth before returning them to their secure place. Remember that pearls do tend to thrive when exposed to light, so don’t be afraid to wear them often.

TYPES OF PEARLS:

AKOYA PEARLS
Also known as cultured pearls, Akoya pearls are the traditional cultured pearl, and are farmed almost exclusively in Japan. These pearls grow in cold waters for short periods of time and have few blemishes. To stimulate the production of nacre, Akoya pearl farmers will insert a relatively large bead into the body of the mollusk to act as the host and catalyst for pearl creation.

SOUTH SEA PEARLS
South Sea pearls tend to grow in warmer climates for longer periods of time. They are typically of lower luster with a higher number of small blemishes than their Akoya counterparts. South Sea pearls are most often graded against each other and not compared to the standards of a quality Akoya pearl. Cultured pearls from the South Sea are mostly white, silver-white, gray or golden, and are considerably larger than an Akoya pearl.

FRESHWATER PEARL
A cultured freshwater pearl is created in a similar fashion to an Akoya pearl, but instead of hosting the nacre on a bead, a small piece of foreign oyster tissue is inserted into the mussel. Freshwater pearls have more irregularities in shape than Akoya or South Sea pearls; they are farmed in Japan, China, and the United States, as well as other locations around the world. The host is always a freshwater mussel rather than a saltwater oyster.

TAHITION PEARL
Tahitian pearls are distinguishable from the other location types from their darker black to gray color range. These pearls are solely farmed in the black-lipped Margaretifera oyster that is native to the South Pacific.