A Buying Guide for Pearls

Cultured pearls offer classic luster and are available in a wide range of colors, sizes and drill types. Read this article to learn about this coveted queen of gems.

A strand of freshwater pink pearls

Types of Pearls


Akoya Cultured Saltwater Pearls

Cultured in salt water, primarily in the seas off the coasts of Japan and China, Akoya pearls are cultured from akoya pearl oysters (Pinctada fucata martensii). Akoya pearls are known for their deep luster, come in a variety of natural colors, and are considered to be the “classic” pearl. According to one legend, the pearl was formed from the tears of the goddess of love. For many, pearls are a symbol of pure heart and mind, of innocence, faith and prosperity.

Akoya pearls are available at Rio inĀ whiteĀ (AA, A grade) andĀ blackĀ (A, A/B grade)Round white Akoya pearl

Round white pearls feature a smooth, creamy bright finish and classic shape that make them ideal for individual use or combined with other colors of pearls and gemstones.

Round black Akoya pearl

The iridescent color of the black Akoya pearl is a bold alternative from classic white and partners beautifully alone or with a variety of gemstones or metal colors.


Tahitian Pearls

Cultured in salt water, primarily the waters surrounding Tahiti and other French Polynesian islands, Tahitian pearls are cultured from black-lip oysters (Pinctada margaritifera). According to one legend, the black pearl was formed from heavenly dew; black pearls symbolize intelligence, strength and prosperity.Ā Tahitian pearlsĀ are traditionally called “black,” but their colors can range from a metallic silver to the darker tones of graphite and may display overtones of blue, purple and green.


Freshwater Cultured Pearls

Freshwater cultured pearls are cultivated in fresh water from mussels, often the triangle sail mussel (Hyriopsis cumingii), that are specially selected for their prolific production of nacre (a hard, iridescent substance that forms the inner layer of certain mollusk shells and also makes up the outer coating of pearls). It is not unusual for a single mussel to produce multiple pearls simultaneously. 


Color-Treated Pearls

Pearls have a porous surface that allows them to be dyed a variety of colors. It is a common practice to treat freshwater pearls in order to achieve a particular or unusual color, and equally common to treat freshwater pearls to create a more evenly-colored strand.

Chocolate pearlsĀ feature a warm brown cocoa color with overtones of rose and copper, making them an excellent accompaniment for rose gold or yellow gold, as well as colored gemstones ranging from yellow to red.

A strand of freshwater color-treated gray pearls

Gray pearlsĀ feature a soft dove-gray color with a metallic sheen. They pair beautifully with silver findings and white gemstones and add luster to a variety of color combinations.

A strand of freshwater color-treated Raven's Wing pearls

Raven’s WingĀ pearls present the dark, complex color of black pearls with iridescent blue-purple undertones and occasional gold overtones.


Pearls Give Shape to New Designs

Cultured pearls are naturally formed in many different shapes. Below are some commonly used terms Rio uses to describe pearl shapes, along with their meanings.

Round: A perfect spherical shape that is considered to be the most valuable.

A strand of round pearls

Rice: An unsymmetrical shape that is oblong.

A strand of rice-shaped pearls

Potato: An unsymmetrical shape with uneven surfaces.

A strand of potato-shaped pearls

Diamond: A flat pearl characterized by a diamond or kite shape.

A strand of diamond-shaped pearls

Coin: A flat pearl characterized by a round shape.

A strand of coin-shaped pearls

Ringed: An unsymmetrical round pearl (potato) characterized by a naturally occuring ring.

A strand of ringed pearls

Keshi: A distict flattened growth pattern characteristic.

A strand of keshi pearls

Button: Resembles a round pearl but has a flat side and a dome side.

A button-shaped pearl

Drop: Symetrically rounded and shaped like a pear or teardrop.

A drop pearl

Understanding Pearl Grades

Pearls are graded based on their luster, shape and color. A pearl’s “luster” is based on how it reflects light no other gemstone available reflects light the way a pearl does. The quality of a pearls luster depends on the thickness and translucence of its layer of nacre. When selecting a pearl to fit within your design and budget, it’s important to understand the different pearl grades and what they mean.

AA-Grade: AA-grade pearls feature a nearly blemish-free surface and present a deep, excellent luster.

A-Grade: A-grade pearls feature surfaces that show a few insignificant blemishes. Their luster is good, exhibiting some depth.

A/B-Grade: On A/B-grade pearls, surface blemishes are easily seen. The pearl luster is moderate. Pearls of this grade, though not perfect, are still beautiful and offer the most economical value.

A selection of handcarved Galatea pearls

credit: Rio Grande

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