Global Gemology - Rare Gems & Jewels
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akoya Pearl

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Art Déco Era akoya pearl necklace with platinum, fine ruby & diamond clasp (c.1930)
Cream colored cultured akoya pearl necklace with platinum, ruby and diamond clasp
Species:  Cultured Pearl
Pearl Type:  Akoya (Bead Nucleated)
Mollusk:  Pinctada Fuctada

​​Mohs Hardness:  2.5 to 4.5 out of 10
Color:  Can be almost any color, but usually white or light yellow, and body color can be modified by pink, green or blue overtones.
RI:  1.350 to 1.685 (+0.009 / -0.005)
Birefringence:  0.155 (use birefringence blink method)
SR/DR/AGG:  Too opaque to test
Spectrum:  Not diagnostic
Fluorescence:  Varies.  Inert to strong light blue, yellow, green or pink under LW and SW.
SG:  2.61 to 2.85
Routine Treatments:  Bleaching
Additional Enhancements:  Dyeing, irradiation, heating, waxing, polishing
SHOP PEARL JEWELRY

akoya Pearl Facts

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Pearls occur in many different shapes, sizes, colors and qualities.
Cultured akoya pearl necklace

Akoya pearls are created by the marine mollusk from the Pteriidae family, known as the Pinctada fucata.

Akoyas are the most popular type of saltwater cultured pearls used in jewelry.

In 1893, Kokichi Mikimoto successfully cultured a pearl in Japan. ​ However, cultured pearls didn't make it to market until 1921.

Nearly all pearls in today's jewelry are cultured.  The pearl culturing process involves surgically inserting multiple bead nuclei into the tissue of certain mollusks.  The mollusk instinctually coats the beads with layers of nacre as a defense mechanism, over time producing a pearl.

Akoya pearls typically range from 2mm to 11mm in diameter.

They're usually spherical or off-round but can also be oval, pear, baroque, or button-shaped.

Akoya pearls' natural colors generally range from white to yellowish, to light pink.

Akoya pearls are cultured in Japan, Australia, China, Hong Kong, Korea & Sri Lanka.

akoya Pearl Gallery

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All photos courtesy of Scott Papper, GIA GG, AJP, CMA (NAJA)

  • HOME
  • ABOUT
  • SHOP
  • SERVICES
    • APPRAISALS
    • EXPERT WITNESS TESTIMONY
    • SELL YOUR JEWELRY
  • GEMOLOGY
    • GEM ENCYCLOPEDIA
    • THE ART OF GEMOLOGY
  • JEWELRY EDUCATION
    • DIAMOND FACTS
    • JEWELER DIRECTORY
    • JEWELRY PERIODS
    • POCKET WATCHES
    • NATIVE AMERICAN JEWELRY
  • GLOSSARY