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Glossary
AT|B|VS|D|E| F |G|H|I| J |K|I|M|NOT| O |P| Q |R| S |T| U | V | W | X | Y | Z
AT
Abalone : Natural pearls forming in the mollusc Haliotis. These pearls generally have a blue iridescence while having a horn shape.
Akoya: Japanese name from akoya-gai given to cultured pearls from the mollusk Pinctada fucata martensii. They are known for their luster and exceptional quality.
Aragonite: Natural crystalline form of calcium carbonate. Aragonite is one of the components of la nacre de perle.
B
Baroque : Term used to qualify pearls with irregular or asymmetrical shapes.
Biwa, pearl: Pearl cultured from the mollusk Hyriopsis schlegeli in Lake Biwa in Japan. This term is often incorrectly used to describe certain freshwater pearls.
Whitening : A treatment commonly applied to the majority of Akoya pearls and freshwater pearls. It is also occasionally used with South Sea pearls and Tahitian pearls.
button, pearl : Term used to describe pearls having a dome shape with a flat side.
VS
conchiolin : Organic substance acting as a glue to bind the calcite and aragonite crystals of the nacre of the pearl.
Calcium carbonate : The main component of pearls (CaCO3)
Circle : term defining the grooves or rings present on the pearl which can modify its shape from minimal to very pronounced.
conch, pearl of : Non-pearly pink to orange-pink pearl produced by the Lobatus gigas shell. These pearls have a very high value due to their rarity and the fact that they cannot be cultivated. Also known as lambi beads, the most sought after will feature a flame pattern on the surface.
Cortez, pearl of : Trade name given to saltwater pearls grown in the Gulf of California, also known as the Sea of Cortez. These dark pearls, presenting a wide range of natural colors of iridescence, are very expensive due to their great rarity. Only about ten necklaces of these pearls are produced each year.
culture, pearl of : Generic term to identify the pearls produced following the human intervention of an insertion of a nucleus or a graft in a fresh or salt water mollusc.
D
Hardness : The hardness of a pearl varies between 3.5 and 4.5 on the Mohs hardness scale.
E
Fresh water, pearl : Generic term used to qualify all pearls developed in a living mollusk in a non-salty environment.
salt water, pearl : Generic term used to qualify all pearls developed in a mollusk living in a salty environment.
G
Generation (first, second, third, fourth) : This term used for both freshwater and saltwater pearls, defines whether the pearl was first developed in a mollusc or whether it was developed in the same organism from which a another generation of pearl had already been removed from the mollusk.
Graft : Term representing the element inseminated into the mollusk to activate the pearl production process.
H
hybrid, mollusk : Variety of molluscs created by crossing various varieties of molluscs to obtain a mollusk capable of producing a particular type of pearl.
I
Irradiation : Treatment sometimes applied to certain cultured pearls consisting in exposing them to gamma rays in order to modify the color of the pearls. The change occurs through a chemical modification of the manganese contained in the mother-of-pearl.
Iridescense : Property of the pearl to change color depending on the angle of view or light.
K
Kasumiga : Japanese freshwater cultured pearl with core named after Lake Kasumi-ga-ura in Japan. The pearls come from a crossing of two types of freshwater mollusk and they are recognized for their unusual color and iridescence. The majority of these pearls are now cultivated in China and often sold under the name "Kasumi pearl", "Kasumiga like" or "Ming pearl".
Keshi : Japanese term meaning “poppy seed”. Keshis are small baroque pearls without a core having been created by accident during the rejection of the mother-of-pearl core by the mollusc from the insemination of a graft during the culture of saltwater pearls. This term is also used to describe the shape of certain baroque freshwater pearls.
I
Chandelier : term designating the quantity and quality of light reflected by the surface and the different layers of mother-of-pearl. Luster is an important factor in the value and quality of a pearl.
M
mabe : A type of pearl constructed (assembled) from a dome of shell mother-of-pearl filled with resin, plastic or wax and closed at the back with another piece of mother-of-pearl so to form a half-pearl. They can be cultured in all types of pearl molluscs, although more common in blacklip and silverlip oysters. Also sometimes nicknamed ''Doublet of cultured pearls'', these pearls are very fragile. The mother-of-pearl layer used is more or less thick and can crack following an impact. Their use on rings or bracelets is therefore not recommended.
Melo, pearl : Natural pearl, yellowish in color, non-pearly, found in the melo melo shell.
South Seas, pearl of : Term representing both natural and cultured pearls produced by the Pinctada maxima mollusk. They are usually white, silver or gold in color.
NOT
Nacre : Interior coating of molluscs with a shiny appearance. Mother-of-pearl is also the outer component of the pearl. Known in English as " mother-of-pearl ".
Nucleus/core : Term representing the element inserted into the pearl to start the production of a pearl, often a pearl bead.
P
Peacock : Term used to qualify a particular natural color of Tahitian pearl varying from dark green-gray to blue-gray through pinkish and purplish hues. This term is also used to qualify the dark color obtained during the irradiation of freshwater pearls, which may have green, bluish or reddish reflections.
Polishing : Action of polishing the pearl to improve its luster.
R
Rice, pearl of : Term qualifying freshwater pearls having the shape and surface reminiscent of the surface of rice.
Round : Qualifier of a pearl whose diameter does not vary in any place by more than 2%.
T
Tahiti, pearl of : Pearls produced in French Polynesia in a saltwater environment by the mollusk Pinctada margaritifera. They are dark colors that can vary from very dark gray (almost black) to shades of pale gray through all the ranges of colors encountered in the Peacock color (green, pistachio, eggplant)
Dye : Method used to change the natural color of a pearl using different dyeing processes. In general, the pearls are first drilled, then immersed in a liquid dye solution, which under pressure will be absorbed by the whole of the pearl which has a porous texture. A dyed pearl that would be sliced in two would therefore have the same color on the inside as on the outside. This treatment is therefore stable.