Buyer's Guide to Island Pearls

Buyer's Guide to Island Pearls

Beautiful, mysterious pearls…what makes each one different?

Here is a guide to the many features and varieties of this treasured gem.


Types of Pearls

All pearls are formed inside of mollusks, and there are four categories that determine types of pearls: saltwater or freshwater, natural or cultured.


Saltwater vs. Freshwater

Three species of mollusks, which are found in coastal waters of the Pacific, produce the majority of saltwater pearls. These include:

·       The Akoya oyster (Japan, China, Australia and New Guinea)

·       The Black-lipped oyster (Tahiti/French Polynesia, and South Pacific)

·       The Silver-lipped or Gold-lipped oyster (South Pacific)

The most common freshwater pearl-producing mollusks, which are found in the freshwater bodies of Asia and North America include:

·       The Wrinkle Shell or River Shell (China, Vietnam, Japan and Korea)

·       The Triangle Shell (China)

·       The Washboard (North America)


Natural vs. Cultured

A pearl is naturally formed in a mollusk when a foreign object enters its body and the mollusk coats it with layers of shell lining (“nacre”) to prevent irritation. Cultured pearls are formed when that foreign object is placed in the mollusk by humans.

The process of cultivation differs slightly for saltwater and freshwater mollusks. For saltwater mollusks, a bead is inserted along with a piece of mantle tissue, a process called “bead nucleation”. Freshwater mollusks are cultivated with “tissue nucleation,” where only a piece of mantle tissue is used.


Pearl of wisdom: A variety of mollusks can produce pearls, but most pearls come from a few select species.


Pearl Grading             

Maui Divers Jewelry utilizes our own proprietary grading system, which was carefully adapted from the GIA (Gemological Institute of America) standard to ensure proper grading of each pearl.

Several factors help determine the quality of a pearl, including size, shape, luster and surface quality.


Millimeters are used to measure the size of all pearls—the diameter of spherical pearls and the width of all other shapes.


Pearls come in many different shapes, but there are seven shapes in three categories that are standard:


Round—The pearl looks round to the naked eye and rolls smoothly across a flat surface

Semi-round—Looks slightly off-round to the naked eye, and will wobble when rolled on a flat surface


Oval—a symmetrical oval shape

Button—a symmetrical flattened shape

Drop—a symmetrical teardrop shape


Semi-baroque—this pearl does not have any symmetry, and may be in any of the shapes above

Baroque—no symmetry, and may be a very odd shape


Pearl Shapes


Surface quality

Pearls will typically have small surface imperfections, abnormalities, blemishes or birthmarks. These birthmarks are what make each pearl unique. Blemish type, size, number, location and visibility determine the surface quality of a pearl. Blemishes may not only affect how a pearl appears, but may also affect how durable it will be. The twelve different types of blemishes that naturally occur on pearls include an abrasion, bump, chip, crack, flat areas, gap, pit, ridge, ring, scratch, spot, or wrinkle.

There are four classifications of surface quality that help determine the severity of the blemishes on a pearl:

·       Clean (perfect or nearly perfect)

·       Lightly blemished

·       Moderately blemished

·       Heavily blemished (severe surface deformities)


Pearls are available in a wide array of colors. The most common include white, cream, silver, gold, gray, black and brown. The color encompasses three characteristics:

·       Body color — the most prevalent color of the pearl

·       Overtone — the luminous color that is in a layer over the body color, and when concentrated on the edges of the pearl is referred to as the “halo”

·       Orient — just below the surface of the pearl is this prismatic layer of coloring

Not all pearls demonstrate all three color characteristics.  And because nature creates many variations of pearl colors, what is shown in each photo is just one example of an extensive range of pearl colors available.


Pearl of wisdom: All pearls have some kind of “birthmark” which makes the pearl unique.

SouthSea ColorsTahitian Colors

Care of your pearls

Pearls are delicate and need to be cared for. These tips will help your pearls stay beautiful for years to come:

* Do not store pearls amongst other jewelry or in an airtight compartment. The surface is soft, and can scratch easily. Store them in a separate cloth pouch.

*Human skin is naturally acidic, and this acid eats away at pearls over time. Wipe your pearls on a regular basis with a soft cloth that is slightly moist to remove the acid.

  • *A mixture of warm water and non-detergent soap should be used to clean pearls every so often. Lay them flat to dry before you put them away.
  • *If you wear pearls frequently, have them restrung annually.
  • *Pearls should be removed when you swim, exercise, wash dishes, garden, apply makeup or perfume or hairspray, and while using any type of harsh detergent or chemical.

Pearl of wisdom: Never wear your pearls while they are still wet.