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107 Cards in this Set
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- Back
- 3rd side (hint)
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Blemishes or irregularities confined to a pearl’s surface. |
Surface characteristics
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7 |
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Only the toughest gems survive to become part of…
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secondary deposits
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21
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... are more common in some colored stone species than in others.
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Large stones with fine color
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35
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Most defects in ... are compromises made by the cutter to produce economically viable gems.
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colored stone proportions
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49
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The wearing away and transport of rock materials by natural forces.
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Erosion
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63
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Crystallization of minerals from a gas.
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Pneumatolysis
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77
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In addition to green, jadeite can be…
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lavender, red, orange, yellow, brown, white, black, or gray
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91
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Trade term for blue tourmaline.
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Indicolite
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105
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A color’s strength or intensity.
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Saturation
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119
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The four major types of cultured whole pearls are …
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akoya, South Sea, Tahitian, and freshwater
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133
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A characteristic enclosed within a gemstone, or reaching its surface from the interior.
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Inclusion
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147
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The smallest group of atoms with both the characteristic chemical composition and crystal structure of a mineral.
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Unit cell
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161
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Dealers routinely use ... to sort large lots of small, round gems into same-size parcels.
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sieves
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175
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Traditionally, the ... a pearl’s shape is from round, the less valuable it is.
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farther
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189
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Top part of the gem above the girdle.
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Crown
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203
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The angles and relative measurements of a polished gem, and the relationships between them.
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Proportions
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217
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Flat stones with ... usually have areas of lower color intensity, called windows.
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shallow pavilions
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231
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If yellow to reddish brown topaz contains ... careful heat treatment can produce a pink color.
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chromium,
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245
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The price of a gem divided by its carat weight.
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Per-carat price |
259
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Description for a gem with no inclusions visible to the unaided eye.
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Eye-clean
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273
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... makes up the bulk of commercial-quality opal on the market.
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White opal
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287
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About 90 percent of the world’s total opal supply comes from ...
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Australia |
301
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triclinic (2) |
amazonite (microcline feldspar), rhodonite |
315
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Mohs of ruby and sapphire |
9
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329
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3 gems colored by nickel
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yellow or green synthetic spinel; synthetic yellow sapphire, natural chrysoprase
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343
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Natural jadeite that’s dyed and often bleached and impregnated with wax or polymers.
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Type C jadeite
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357
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An opening that extends into a gem from the surface. |
Cavity
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371
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Trade term for a highly prized, vivid blue adularescence displayed by the finest moonstone.
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Blue sheen
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385
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Most citrine on the market is produced by heat treatment of ...
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amethyst
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399
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Primary mining (1) - lapis
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Afghanistan
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413
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3 quality judgement factors for turquoise.
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color, texture, matrix
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427
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A pearl formed as the result of human intervention in the formation process. |
Cultured pearl
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441
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Chinese freshwater cultured pearls shaped and textured like rice grains. |
Rice pearls
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455
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gem - trade term "fools gold"
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pyrite
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469
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Most common treatment - ruby
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heat treated; almost are
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483
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Describe Vietnam rubies
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similar to Mogok
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497
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What is a Thai/Pailin ruby?
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Thail & Pailin - pure red to brownish red to purplish red hue med dk to very dk; no fluoresence; black extinction; aka Thai or mud rubies
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511
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What % of blue sapphire does US buy?
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50%
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525
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Three main elements in tanzanite, plus color element
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silica, calcium, and aluminum - color change vanadium
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539
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Exposing a gem to rising temperatures for the purpose of changing its appearance.
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Heat treatment
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553
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Color element - iolite
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iron
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567
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What is chrysolite?
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yellow chrysoberyl
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581
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Because retailers deal directly with consumers, they must have complete confidence in their ...
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wholesalers
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595
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What color is imperial topaz?
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imperial topaz - medium reddish orange to orange red color
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609
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What color does Brazil and Sri Lanka produce for topaz?
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colorless
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623
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gem - trade name "Pink emerald"
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morganite
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637
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Lacking a regular crystal structure. |
Amorphous
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651
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What gem was discovered in 1897 by Maynard Bixby?
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red beryl
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665
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finest quality aquamarine
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strong, medium dark blue to slightly greenish blue
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679
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Opal was found in ancient mines in what country?
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slovakia
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693
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What two countries cut the most opal?
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Chian and Germany
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707
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What is black crystal opal?
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dark background, transparent to semitransparent It is valued for its strongly hued play of color
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721
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Most gems are …
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minerals
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735
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Where is moonstone mined primarily?
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Sri Lanka
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749
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Type of gem - amazonite
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feldspar
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763
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The most valuable star corundum has bodycolor that provides a ... to the star. |
strong contrast
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777
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care issues with kunzite
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color fades with exposure to bright light and heat
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791
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The cutter’s main goal is to produce a stone with the …
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highest possible value
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805
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When were tourmalines recognized as distinct species? |
1800
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819
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When did Chrome tourmaline hit the market?
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1960s
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833
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what is indicolite?
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blue tourmaline
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847
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A cryptocrystalline quartz aggregate.
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Chalcedony
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861
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crystal system garnets; shape
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cubic crystal system; dodecahedron
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875
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mining (3) for spinel |
Sri Lanka, Afghanistan, Tajikistan; occurs with corundum
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889
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color range of tsavorite
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slightly bluish green to yellowish green
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903
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A special kind of interference phenomenon that breaks up white light into its spectral hues. |
Diffraction
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917
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Change in speed and possible change in direction of light as it travels from one material to another. |
Refraction
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931
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host rock almandite
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largest sources are usually metamorphic rocks like schist
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945
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color element rhodolite? |
iron (almondite); magnesium (pyrope)
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959
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The use of collectors’ gems in jewelry is limited by a combination of factors that might include … |
scarcity, lack of promotion, and poor durability
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973
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mining (2) for demantoid
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Russia (high quality); Central Namibia (large, but no horsetails; good quality)
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987
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A cylindrical synthetic crystal produced by the flame-fusion process.
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Boule
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1001
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A synthetic-crystal growth method that starts without a seed crystal.
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Spontaneous nucleation
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1015
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Other than types A-C, what are other type of jadeite treatments
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heat treatment
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1029
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treatments amber
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heat in oils (oils penetrates and fill bubbles that cause cloudiness; cause sun spangles) stained (to age) dyed, ambroid (pressing small pieces together under gentle heat or pressure)
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1043
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treatment for conchiolin coral |
golden can be bleached black coral; coral becomes more coarse than black coral
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1057
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... are the most widespread minerals on earth.
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Feldspars
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1071
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when did tortoises become protected?
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protected since 1975; bans largely ignored in Caribbean
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1085
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what gem is sold as new age jewelry? |
moonstone |
1099 |
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Turquoise that’s (2) is commonly treated to improve color and texture. |
porous and coarse
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1113
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color range obsidian
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gray to black, often spotted with white, as well as brown to red
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1127
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finest quality emerald
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bluish green to green with strong vivid sat and med to med/dk tone; trasnparent; evenly distributed color w/o zoning
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1141
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Describe quality output at Columbia's 4 emerald mines
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Columbian Mines - Muzo (Bright pure green, some bluish green) Chivor (bluish green), Coscuez (Bright green "Green fire", La Pita (not as yellow as Cosquez, not as blue as Chivor; most significant producer in Columbia)
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1155
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what is the mantle?
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mantle - the organ that lines the mollusk's shesll, encloses its soft body, and contains the cells that form pearl sacs, and secrete nacre
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1169
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Tsavorite is colored by ... and the best is vivid green, with medium to medium-dark tone.
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vanadium,
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1183
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Many historically important red gems, long identified as ruby, were recognized as ... in the 1800s.
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spinel
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1197
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A gem dealer’s term for a random sample from a parcel of gemstones, often used to assess the parcel’s overall quality.
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Cut
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1211
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A gem-producing area, or a particular mine in that area.
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Source
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1225
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Without exposure to natural or artificial radiation, ... can’t cause color in gems.
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color centers
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1239
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... that make gems more available and affordable are an important part of today’s gem and jewelry market.
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Treatments
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1253
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Ruby rates ... on the Mohs hardness scale, so it’s ideal for frequently worn jewelry.
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9
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1267
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The most highly valued blue sapphires are (3)
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velvety blue to violetish blue, in medium to medium-dark tones, with strong to vivid saturation
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1281
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... is one of the world’s largest sources of dark blue, commercial-quality sapphires.
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Australia
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1295
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(4) provide most of the world’s emeralds.
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Colombia, Zambia, Brazil, and Zimbabwe
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1309
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... is the most convincing tanzanite imitation to date.
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Synthetic forsterite
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1323
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Most gem tourmalines are ... that form in pegmatites.
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elbaites
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1337
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(2) are rarely treated.
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Garnet and spinel
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1351
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size range freshwater pearls
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2-13 mm
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1365
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what is one of the most common materials on earth that is also a gem?
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quartz
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1379
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Describe quality of Rio Grande de Sul/Uruguay
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Rio Grande de Sul (extense into Uraguay, 4 inches long, lighter in tone, but no brown tinges)
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1393
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finest quality of ametrine
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medium dark to moderately strong orange and vivid to strong purple or violetish purple; sharp half and half boundary
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1407
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most common treatment adventurine?
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commonly dyed to produced colored, inexpensive gemstones; often dyed to resemble jade
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1421
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what kind of quartz crystalite is carnelian? |
cryptocrystalline quartz |
1435
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Describe quality emerald from Muzo mine |
Bright our green, some bluish green |
extra1 |
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Describe Chivor emeralds |
bluish green |
extra2
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describe Cosquez emeralds |
bright green "green fire" |
extra 3 |
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describe La Pita emeralds |
not as yellow as cosquez, not as blue as chivor, most significant producer in Columbia |
extra 4 |
