Posted on

Glossary of Pearl Terms O

Glossary of Pearl Terms O

Occidental pearls: Historical term used to describe natural pearls from Mexico, dates to the 16th century but fell from usage after 1930.

oil pearls: Imitation pearls worked from the columella (see) of the Trochus and Turbo snails.

oiling: Process of soaking a natural or cultured pearl in warm oil to diminish the visibility of cracks.

opera necklace: Pearl necklace measuring 28 to 35 inches (70-90 cm).

operculum: Shell-like cover that closes the opening of some marine gastropod shells.

Orama Pearls: Trade name for cultured blister pearls sold to tourists on Rarotonga in the Cook Islands.

organic dyes: Used to change the color of natural and cultured pearls.

orient: Optical phenomenon that produces iridescent colors on the surface of some natural and cultured pearls. One or more of these factors creates orient: reflection, refraction, diffraction, and thin-film interference.

Oriental pearls: Historical commercial term for natural marine pearls from the Persian Gulf and the Red Sea.

Osmena pearl: Also called Osmend or Osmenda pearl. Imitation pearl worked from the inner coil of the Nautilus pompilius shell.

ostracum: Central, prismatic layer of a bivalve mollusk shell.

ounce pearls: Historical trade term describing small natural pearls offered in lots.

oval: Natural or cultured pearl in an oval or egg shape.

overtone: Secondary color on the surface of a natural or cultured pearl. It is created by nacre layers interfering with white light and splitting it into its component colors.

oyster: Common name correctly applied to some bivalve mollusks and incorrectly to others. No bivalve mollusk that produces nacreous natural or cultured pearls is a true oyster.

oyster pearls: Chalk-like natural pearls produced by edible oysters (Family Ostreidae), low in commercial value.

Posted on

Glossary of Pearl Terms M

Glossary of Pearl Terms M

mabe: Originally, the Japanese trade term for an assembled blister pearl grown in Pteria penguin. In Japanese, that mollusk?s name is mabe-gai, hence the pearl?s name. Today, the word is used to describe any assembled blister pearl.

maeshori: Originally in Japan, a deep-cleaning process used before bleaching akoya cultured pearls. Today, “maeshori” (literally, “before treatment”) retails its original meaning, but is also the name of several treatments used to enhance the luster or most Chinese freshwater, and some South Sea and akoya cultured pearls.

Magan Moshe Pearl: Natural abalone pearl weighing 349.41 carats. It was purchased by Moshe Pereg and given its name in 1989.

majhoolah: Historical Persian quality factor describing a blister pearl from which a round and better pearl might be removed by peeling.

Majorica pearl: Imitation pearl created by coating a glass nucleus with essence d?orient (see). The pearly essence is made from guanine crystals extracted from scales on the undersides of certain fish.

Manihiki Pearl Producers? Association: Association of Pinctada margaritifera cumingi pearl producers in the Cook Islands.

mantle: Organ lining the shell of freshwater and saltwater bivalve mollusks.

mantle graft tissue: Tiny piece of tissue cut from a donor mollusk?s mantle and implanted with or without a bead nucleus in a host mollusk to produce a cultured pearl. The outer epidermis of the mantle is made up of epithelial cells that secrete nacre.

maona pearl: Samoan term for imitation pearl created from the operculum (see) of Turbo petholatus.

margarita: Greek and Latin word for pearl.
margaritifera: Genus name (capital M) applied to a group of freshwater mussels, and the species name (lowercase m, genus Pinctada) applied to the black-lip pearl mollusk.

master set: Group of pearls used for comparison to assess the quality characteristics of cultured pearls submitted for grading.

matching: Matching pearls for uniformity in a strand or piece of finished jewelry.

matinee length: Pearl necklace measuring 20 to 24 inches (50 to 60 cm).

mature pearl: Natural pearl described as being of the most beautiful water (see).

melo pearl: Natural non-nacreous pearl found in the Melo melo marine gastropod.

Mikimi: Trade name for second or third grade Majorica imitation pearls.

Mikimoto, Kokichi: (March 10, 1858 ? September 21, 1954) First person to commercially produce spherical cultured pearls using the Mise-Nishikawa method of pearl culture, which that pair most likely learned from Englishman-turned-Australian William Saville-Kent.

Mikimi: Large beaded freshwater pearls grown in the mollusc gonad in lieu of the mantle. See also Edison Pearls.

Miyoko pearls: Imitation pearls marketed in Germany in 1983.

Mise-Nishikawa method: Method of saltwater pearl culture by which a bead nucleus and piece of donor-mollusk mantle tissue are implanted in the gonad of a host mollusk. The technique was most likely first developed by Englishman-turned-Australian William Saville-Kent.

Mise, Tatsuhei: With Tokishi Nishikawa, credited (probably erroneously) in the early 1900s with developing the method of saltwater whole pearl culture still used today.

Mitsubishi pearls: First pearls produced in Pinctada maxima by Dr. Sukeyo Fujita between 1928 and 1932 on the Malaysian Island of Sulawesi. The project was financed by Baron Iwasaki of the Mitsubishi Company.

mollusk: Any invertebrate from the phylum Mollusca.

momme: Japanese weight unit used to valuate cultured pearls. One momme equals 3.75 grams.

mother-of-pearl: Iridescent layer (principally calcium carbonate and conchiolin, see) lining the inner shell of some mollusk species. When it coats a bead to form a cultured pearl or composes a natural, tissue-cultured or keshi pearl, it?s called nacre (see).

muta?a: Historical Persian quality factor describing baroque pearls.

Posted on

Glossary of Pearl Terms N

Glossary of Pearl Terms N

nabatee: Arabian term for sugar used to describe pearls from the Persian Gulf that had a slightly off-white, yellowish color.

nacre: Aragonite and calcite platelets bound together by conchiolin that completely compose bivalve and abalone natural pearls, keshi, tissue-cultured freshwater pearls, and the coating on the nucleus of bead-cultured and bead-and-tissue-cultured pearls.

nacreous: Composed of nacre.

nacre thickness: Measured in whole and decimal fractions of millimeters, the depth of the nacre layer on the bead nucleus of bead-cultured and bead-and-tissue-cultured pearls. Not a consideration for natural and cultured pearls composed entirely of nacre (see).

Nassau pearl: Historical term for conch pearl.

National Federation of Pearl Cultivators? Cooperative Association (Zen Shin Ren): Japanese association that organizes hama-age auctions.

National Pearl Research Laboratory: Established in 1952 in Mie Prefecture, Japan, with the intention of improving pearl culture technologies.

natural pearl: Organic gem created in a mollusk without human intervention.

Nautilus pearl: Natural pearl from Nautilus pompilius, extremely rare. Osmenda imitation pearls are often incorrectly called nautilus pearls.

nimro: Historical Persian quality factor describing blister pearls.

Nishikawa, Tokishi: Credited with Tatsuhei Mise (probably erroneously), with discovering the bead-and-tissue method of whole pearl culture.

non-beaded cultured pearl: Cultured pearl grown without a bead nucleus.

non-nacreous pearl: Natural pearl lacking a nacreous surface layer.

non-nucleated cultured pearl: Cultured pearl grown without a bead nucleus.

nucleus: Bead implanted in a host mollusk, most often with a tissue piece, to become the core of a cultured pearl.

nuggets: Semi-round pearls that resemble gold nuggets.

Posted on

Glossary of Pearl Terms K

Glossary of Pearl Terms K

karasu-gai: Japanese term for the Cristaria plicata (cockscomb) freshwater pearl mussel.

kago: Japanese term for pearl mollusk baskets suspended from longline systems.

kan: Historical Japanese weight unit used to valuate pearls. One kan equals 1,000 momme (see), 3.75 kilograms and 8.26 pounds.

kangaroo basket: Underwater basket in which pearl mollusks are stored for a short period after the grafting process. The baskets have individual pockets meant to catch expelled nuclei.

koao: Coral platforms on which pearl farms are built on Manihiki atoll in the Cook Islands.

kashra: Historical Persian quality factor describing blister pearls.

Kasumigaura cultured pearl: Cultured pearl grown in Japan?s Lake Kasumigaura in a hybrid freshwater pearl mussel (Hyriopsis schlegeli/Hyriopsis cumingi).

keshi: Japanese term for ?poppyseed.? Originally, the term referred to a small natural or cultured pearl.

keshi cultured pearl: Trade term for a saltwater pearl produced as an accidental byproduct of the pearl culturing process.

khardil: Historical Persian quality factor describing black pearls.

Komatsu flower pearl: Original faceted cultured akoya pearl developed by Japan?s Komatsu Diamond Industry Company in 1992.

koshimono: Japanese term for cultured akoya pearls grown for two years.

Kunz, George Frederick: With Charles H. Stevenson, author of The Book of the Pearl, published in 1908.

Kuri Bay: Site of the first successful Australian South Sea pearl farm, founded in 1956 in remote Western Australia. The site was named for Tokuichi Kuribayashi, president of Japan?s Nippo Pearl Company, which owned the Arafura Pearling Fleet.

Kuta pearl: Cultured blister pearl grown in Pinctada maxima off the island of Bali. A section of sea urchin is embedded in the resin when the blister is filled to form a mabe pearl.

Posted on

Glossary of Pearl Terms L

Glossary of Pearl Terms L

L-grade: Letter grade assigned to low-grade pearls by Japan?s Pearl Inspection Offices from 1952 to 1998.

La Paz pearls: Natural pearls from Central America.

lacquer coating: Temporary coating applied to some imitation and cultured pearls to enhance their color and luster.

Lake Biwa: Located northeast of Kyoto, Lake Biwa is Japan?s largest freshwater lake and site of that country?s first freshwater pearl culture operations, headed by Dr. Masao Fujita.

Lake Kasumigaura: Located northeast of Tokyo, Lake Kasumigaura is Japan?s second largest freshwater lake and origin of Kasumigaura (Kasumi, Kasumiga) pearls.

Lamprotula leai: Freshwater mussel native to China. The mussel is a source of bead nuclei but is not used in pearl culture.

lantern baskets: Baskets used to hold young mollusks when suspended from lines during saltwater pearl culture. Method is most often used for akoya mollusks for a short period after they are bred in hatcheries.

laser treatment: Supposed method of modifying a cultured pearl?s color. It is often claimed but does not actually exist.

Latendresse, John: (July 26th, 1925?July 23, 2000) A pioneer of freshwater pearl culture in the United States.

lead nuclei: Used by Mikimoto in his early attempts at akoya pearl culture. The attempts failed.

liang: Historical weight unit used to valuate pearls in China. One liang equals 1/10 or 1/16 jin. One jin equals 500 grams.

lianzhu: Historical Chinese quality factor that described the finest quality natural pearls.

ligament pearl: Defunct trade term once used to describe a natural pearl formed within the mantle isthmus, just below the ligament.

light pearl: One of four Saxony quality levels used to describe natural German river pearls. A light pearl was of the finest quality. See also: half-light pearl (high quality), sand and rotten pearl (the lowest qualities).

Linn?, Carl von: (May 13, 1707?January 10, 1778) Also known as Carolus Linnaeus. In 1758 he originated the binomial system of zoological taxonomy that has been used since. He was the first person to culture whole pearls.

lion?s paw pearls: Non-nacreous scallop pearls that exhibit white, pink, violet and/or orange colors.

Little Willie: Discovered by Bill Abernethy in Scotland in 1967. This natural freshwater pearl is round, meaures 11.6 mm and weighs 34 grains (8.5 carats). Same as Abernethy Pearl.

longline systems: Horizontal lines stretched between buoys and anchored to the bottom at both ends. Chaplets (vertical lines) with baskets or net panels of nucleated mollusks are suspended underwater from the longlines.

luli: Ancient Roman imitation pearls made from glass with a coating of silver and another layer of glass.

luster: Quantity and quality of light reflected from the surface or just under the surface of a natural or cultured pearl.