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Questions and Answers
What is the highest match grading for pearl quality?
What is the main purpose of buffing pearls?
How are pearls matched and strung?
When processing pearls, what is one reason they are drilled ?
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What is the lowest grading for pearl quality?
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How are pearls sorted after harvest?
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What is the term for a bunch of pearls that consists of 5 or more strands?
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What is the term used to describe the quality of nacre in pearl grading?
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What is the term used to describe the presence of scratches on the surface of a pearl?
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What is the term used to describe an irregular bulge on the surface of a pearl?
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What is the term used to describe an area where the nacre has not covered the nucleus?
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What is the grading term used to describe pearls with noticeable blemishes?
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What is the grading term used to describe the nucleus being visible through the nacre?
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What is the term used to describe a pearl with a dull appearance?
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What is the grading term used to describe pearls with no noticeable blemishes?
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What is the primary component of nacre in pearls?
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What is a term for non-nacreous pearls that lack a specific arrangement of aragonite crystals?
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What is the GIA term for pearl colors that are not neutral or near-neutral?
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What is the typical shape of conch pearls?
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What is the size range of most pistachio pearls?
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What is the characteristic of melo pearls in terms of size and shape?
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What is the GIA term for pearl colors that include white, gray, and black?
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What is the composition of nacre in terms of chemical compounds?
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What is the characteristic of a cultured pearl with a chalky appearance?
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What is the term for one or more translucent colors that lie over a pearl's bodycolor?
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Which of the following is a characteristic of high-quality nacre?
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What is the term for the evidence of a cultured pearl's bead nucleus through the nacre?
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Which type of Fresh Water pearl is known for its high luster and wide color range?
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What is the term for the distinct phenomena exhibited by some orange melo pearls?
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What is one factor that affects the value of Akoya pearls?
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Which of the following is NOT a characteristic of a high-quality pearl?
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What is the characteristic luster of South Sea pearls?
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What is the characteristic of a cultured pearl with no evidence of its bead nucleus through the nacre?
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Which type of pearl has a 'Peacock' dark green-gray to blue-gray body color with pink to purple overtones?
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What is the typical size range of South Sea pearls?
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What is the characteristic color range of Akoya pearls?
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What is the typical average size of Akoya pearls?
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What is the characteristic color range of 'Aubergine' Tahitian pearls?
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What is the primary factor that affects the demand of a pearl, in addition to its rarity?
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What is the primary purpose of a clean environment during a pearl's growth?
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What is the characteristic of a pearl that is considered the most valuable in terms of shape?
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What is a necessary condition for any cultured pearl for it to have significant value?
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What is the term for the surface irregularities of a pearl?
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What is the purpose of the process that includes cleaning, buffing, and sometimes bleaching, in cultured pearls?
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Study Notes
Types of Pearls
- Tahitian pearls: round, near-round, and baroque
- Freshwater pearls: round and near-round
Main Synthetic Process
- Cultured pearls: type of synthetic pearl
Common Imitation Material
- Essence'd Orient: a mixture of iridescent fish scales and varnish used to coat glass beads, plastic, or mollusk shell
Culturing and Trading Process
- Processors: most prominent in Japan and China
- Manufactures buy from processors or dealers or directly from farmers
- Dealers sell to retailers and manufactures
- Dealers buy directly from farmers, other dealers, cooperative marketplaces, or at an auction
- Auctions take place in Tahiti, Hong Kong, Japan, and Australia
- Some auctions are by invitation only
- Online sales happen with dealers in Tokyo to Hong Kong
Post-Harvest Procedures
- Sorting: by color, size, and amount of blemishes
- Drilling and cutting: full or half, or making three-quarter-cut pearls to hide or remove blemishes
- Bleaching: widely used, not considered a treatment
- Buffing: using walnut shells or ground corn cobs with wax; tumbled or vibrated
- Matching and stringing: strung within one-half millimeter of each other in diameter, on silk or nylon with 5 or more 14" or 16" strands making a "hatch"
Grading and Quality
- Match Grading:
- Excellent: pearls are uniform in appearance and, if drilled, drilled on center
- Very Good: very minor variations in uniformity
- Good: minor variations in uniformity
- Fair: noticeable variations in uniformity
- Poor: very noticeable variations in uniformity
- Nacre Quality Grading:
- Acceptable: nucleus not noticeable; no chalky appearance
- Nucleus Visible: the cultured pearl shows evidence of its bead nucleus through the nacre
- Chalky Appearance: the cultured pearl has a dull appearance
- Blemishing Grading:
- Clean: pearls can be blemish-free (spotless) or contain minute blemishes that are very difficult to see
- Lightly Spotted: pearls show minor surface irregularities
- Moderately Spotted: pearls show noticeable blemishes
- Heavily Spotted: pearls show obvious surface irregularities that might affect durability
Forming Source
- Akoya Saltwater pearls: from "Pinctada fucata" or "Pinctada chemnitzii" oyster
- South Sea pearls: from "Pinctada maxima" oyster, can be nucleated up to three times with the third nucleation producing the largest cultured pearl
- Tahitian Pearls: from "Pinctada margaritifera" oyster
- Fresh Water Pearls: from "Hyriopsis cumingii" (triangle mussel) or "Hyriopsis schlegelii" (Biwa mussel), hybrid of both "Leisure mussel"
- Soufflé pearls: large, lightweight baroque Chinese freshwater cultured pearls with high luster and a wide color range with 11 mm to 14 mm diameter
Crystal Structure
- Three basic methods to produce whole freshwater cultured pearls: mantle tissue nucleation, second-generation production, and coin-bead/spherical-bead (CBSB) production
Possible Phenomena
- Flame Structure: Orange melo pearls can exhibit distinct flame structure
- Overtone: one or more translucent colors that lie over a pearl's bodycolor
- Orient: increases value for its beautiful, usually indicates thick, high-quality nacre, and it's rare and desirable
- Luster: caused by light traveling through translucent layers of nacre and reflecting back to the eye
Clarity Characteristics
- Surface Texture: Nacre Grading, Thickness, Translucence, Layer uniformity, Layer alignment
- Luster:
- Excellent: reflections are bright, sharp, and distinct
- Very Good: reflections appear bright and near-sharp
- Good: reflections are bright but not sharp and slightly hazy around the edges
- Fair: reflections are weak and blurred
- Poor: reflections are dim and diffused
Blemishes
- Abrasion: a series of scratches on the surface of a pearl
- Bump: an irregular bulge, blister, or welt, usually too small to affect basic shape
- Chip: an opening or cavity in the surface
- Crack: a surface-reaching break or fracture in the nacre, or a break or fracture in the nucleus
- Flat: a flat section on an otherwise spherical pearl, usually too small to affect basic shape
- Gap: an area where the nacre has not covered the nucleus
- Pit: an indentation or depression, found individually or in a group
- Scratch: a thin groove or depression in the surface
- Spot: an area that is darker, lighter, or more dull than the surrounding nacre
- Wrinkle: an irregular ridge or crease on the surface
Trade Names
- South Sea: "Golden Lipped Oyster" or Silver Lipped
- Tahitian: "Black Lipped Oyster", "Peacock", "Aubergine", "Pistachio"
- Fresh Water: "Edison Pearls" (higher quality than Soufflé pearls) or "Fire Balls"
- Apricot: Light pinkish orange Chinese freshwater cultured pearls
- Aubergine: Tahitian cultured pearls with a dark grayish purple bodycolor
- Golden: Strong greenish yellow to orangy yellow South Sea cultured pearls
- Lavender: Light pinkish purple Chinese freshwater cultured pearls
- Peacock: Tahitian cultured pearls with a dark green-gray to blue-gray bodycolor and rosé to purple overtones
- Pistachio: Tahitian cultured pearls with a yellowish green to greenish yellow bodycolor
Countries of Origin
- Natural pearls were farmed off the Persian Gulf
- Akoya cultured pearls are produced in Japan, China, and Vietnam
- Korea, Southeast Asia, Australia, the Red and Mediterranean seas, the Persian Gulf, the South and East African coasts, and the Caribbean
Largest Consumers
- By 1920, Mikimoto had begun marketing cultured whole pearls internationally
- Post World War 11 the first South Sea cultured pearl farm was founded in Western Australia in the 1950s
- The first Tahitian cultured pearl farm was started on Manihi Atoll in French Polynesia in the 1960s
- Chinese freshwater cultured pearls appeared on the international pearl market around 1970
Mohs Scale
- Poor to Good
Variety/Species/Group
- Organic Gem
Color/Hue Range/Value
- Akoya: white with rosé overtone and excellent luster, 2 to 11 mm in diameter, with an average size of 6 to 8 mm (large increase in value from 7 to 7.5 mm and 8 mm)
- South Seas: two varieties of P.maxima, gold, cream, yellow, silver in color, soft, satiny luster; gold-lipped and silver-lipped shells, with pearls ranging from 8 to 20 mm, with most falling between 10 and 15 mm
- Tahitian: "Peacock" dark green-gray to blue-gray bodycolor with pink to purple overtones, "Aubergine" is dark grayish purple bodycolor, "Pistachio" yellowish green to greenish yellow bodycolor, 8 mm to 17 mm, with most falling between 9 mm and 14 mm
- Fresh Water: colors that include creamy white, lavender to purple, pink, orange, blue, and golden, round and near-round, range from 4 to 14 mm (larger can be above 19mm)
- Non-nacreous Pearls: Conch Pearls - pink and are rarely spherical, most are oval or irregular in shape, with lengthwise dimensions almost always under 10 mm, Melo Pearls - Orange, large and spherical, and between 20 and 30 mm in diameter
Chemical Composition
- Nacre: microscopic platelets of aragonite, crystallized form of calcium carbonate, a chemical compound of calcium, carbon, and oxygen, Nacre also contains conchiolin
- Non-nacreous Pearls: aragonite crystals are arranged in columns that are mostly perpendicular to the pearl's surface, not all non-nacreous pearls have this, but those that don't are called "porcelaneous"
Pearl Value Factors
- Rarity of larger pearls increases their value
- Demand and rarity of a pearl color increase its value
- Luster of a pearl is improved by cool water and a clean environment during growth
Pearl Characteristics
- Round is the rarest and most valuable cultured pearl shape
- Acceptable nacre quality is required for a cultured pearl to be of significant value
- The farther a pearl's shape is from round, the less valuable it is
Pearl Sorting and Matching
- A large quantity of pearls is required to end up with a well-matched group
Pearl Color and Appearance
- All pearls display bodycolor, and some also have overtone or orient or both
- Blemishes are irregularities confined to a pearl's surface
- Circled pearls have one or more grooved or ridged rings all the way around them
Pearl Treatments and Imitations
- Process: a procedure that includes cleaning, buffing, and sometimes bleaching to make cultured pearls presentable and appealing
- Full-drilled: a cultured pearl with a hole drilled all the way through, sometimes called drilled-through
- Essence d'orient: a mixture of clear varnish and fish scales used in making imitation pearls
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Description
This quiz is about cultured pearls, their production process, and the differences between them and imitation materials. It covers the main synthetic process, common imitation materials, and the trade center for pearls.
