Glossary of Pearl Terms U
Unio: Genus in the Unionidae freshwater mussel family. Several species in the genus produce pearls.
underwater platform: Used in French Polynesia as a temporary care station from which mollusks are suspended after implantation of a bead nucleus and donor-mollusk tissue piece.
uroko: Japanese term for scaly spots on akoya cultured pearls.
Glossary of Pearl Terms V
Venezuelan necklace: Legendary strand of pearls owned by Spain?s Queen Isabella.
Venus pearls: Natural non-nacreous pearls from Veneridae-family saltwater mollusks that are often called Venus clams.
virgin pearl: Historical term for an undrilled or freshly harvested pearl.
Vologne pearl: Natural freshwater pearl from the French province of Lorraine, specifically from the Vologne River.
Glossary of Pearl Terms W
Wada method: Developed by Dr. Koji Wada of Japan, a method of choosing donor-mollusk mantle tissue to help determine a cultured pearl?s color.
wampums: Cylindrical beads made from quahog shells by native Americans and used as jewelry or money.
Wan, Robert: Founder of the Tahiti Perles Company, which became the largest producer of Tahitian cultured pearls.
warm hues: Colors from purplish red to orangey yellow to greenish yellow, as defined by the GIA color-reference chart.
water: Historical trade term used to describe the translucency of a pearl.
wax pearls: Imitation pearls made from hollow glass spheres filled with wax, popular during the early 20th century.
waxing: Application of wax to a pearl?s surface to enhance its luster.
wings: Natural pearls shaped like wings.
Winston Pearl, The: Natural freshwater pearl measuring 44 mm in diameter and weighing 601.24 grains purchased by New York jeweler Harry Winston in 1987. It?s believed to be the largest freshwater pearl in the world.
wooden wedge: Used to separate the valves of a host pearl mollusk so a donor-mollusk tissue piece or bead and tissue piece can be implanted.
working: Removing layers of nacre from a natural or cultured pearl.
World Pearl Organization: Formed in Japan in November 1994, it engages in public relations and caters to the interests of pearl producing and consuming countries.
Glossary of Pearl Terms X
X-ray testing: Used to determine whether a pearl is natural, cultured or imitation.
Glossary of Pearl Terms Y
yakkah: Historical Persian quality factor describing natural pearls of secondary quality.
yellow grains: Nineteenth century theory of natural pearl production stating that yellow grains found in some freshwater pearls were from shell-production reserve material. This organic material made its way into the mantle and catalyzed pearl growth.
yoyo: Japanese term for a host mollusk?s 45-day convalescence period after implantation of a bead nucleus and donor-mollusk tissue piece.
Glossary of Pearl Terms Z
zebra mussel: Predatory mussel that has done significant damage to freshwater mussel stocks in streams and rivers principally north of the Ohio River in the eastern United States.
zuchtperlen: German term for cultured pearls.