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103 Cards in this Set
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- Back
- 3rd side (hint)
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A pearl with one or more grooved or ridged rings all the way around it. |
Circled pearl
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2
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Superheated, pressurized water can transfer minerals in solution and redeposit them in…
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veins to form gems
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16
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Terms often used in the jewelry industry to describe particular gemstone colors or link gems with specific geographic locations.
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Trade terms
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30
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Know a gem’s ... before you grade it.
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identity
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44
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A deposit where gems are eroded from their source rock, then transported away from the source and further concentrated.
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Alluvial deposit
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58
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Rock altered by heat and pressure, or by heated fluids from magma.
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Metamorphic rock
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72
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A “foreign crystal” that formed in unrelated rocks and was brought to the surface as a passenger in magma.
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Xenocryst
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86
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The chemical differences between … are subtle enough to allow both to be called jade.
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nephrite and jadeite
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100
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Dark areas in a faceted transparent colored stone.
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Extinction
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114
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People have coveted natural pearls as symbols of wealth and status for …
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thousands of years
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128
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A gemstone’s ability to withstand wear, heat, and chemicals.
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Durability
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142
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How well a gemstone resists breaking and chipping.
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Toughness
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156
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Large gems are more rare than small ones, so they often cost much more per carat, even if they’re of ...
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equivalent quality
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170
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An opal imitation made of glass that appeared in the late 1970s.
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Slocum Stone
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184
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Light that eventually returns to the eye after entering a gem through the crown, reflecting off its pavilion facets, and exiting back through the crown.
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Brilliance
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198
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Horizontal spinning metal disk used to grind or polish a gem’s facets.
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Lap
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212
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Cutters take less care with inexpensive, low-quality rough, so finished stones often have proportion ...
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variations
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226
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Because of its ... topaz requires special care in cutting, polishing, mounting, and wear.
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cleavage,
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240
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Tone and saturation levels distinguish ... from emerald.
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green beryl
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254
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Tiny nicks and pits caused by wear and damage to a gem’s facet edges or culet.
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Abrasions
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268
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A linear scrape, normally seen as a fine, curved or straight, white line.
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Scratch
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282
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... is often considered the most desirable play-of-color hue.
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Red
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296
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zircon
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tetragonal (1)
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310
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toughness of corundum
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excellent toughness
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324
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10 gems colored by chromium
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red spinel, ruby, pink sapphires, pink topaz, jadeite, demantoid garnet, chrome pyrope, chrome diopside, alexandrite, emerald
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338
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The medium texture category of jadeite.
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Relatively old mine
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352
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A gem’s (2) depend on the types of atoms it’s made of, and how closely they’re packed together.
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density and specific gravity
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366
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Minute inclusion enclosed within a gem; can occur singly or in groups called clouds.
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Pinpoint
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380
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Amethyst is sold in a variety of grades based mainly on ...
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color
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394
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What is the world's oldest known commercial stone?
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lapis
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408
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What is sabzi lapis?
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greenish lapis, confused with turquoise
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422
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Common name for the Pinctada fucata oyster and the natural or cultured pearls it produces.
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Akoya
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436
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The natural substance produced by pearlbearing mollusks to make pearls.
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Nacre
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450
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color element - Rhodochrosite
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manganese
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464
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crystal habit ruby
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tabular hexagonal prism; also elongated prisms and bipyrameds
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478
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When were thai gem deposits depleted?
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1990s
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492
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3 cutting nations for rubies
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Thailand for mass market; Switzerland for high end; India for commercial quality
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506
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% of blue sapphires that are treated
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95%
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520
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Describe a Kanchanaburi blue sapphire
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Kanchanaburi - greenish, grayish, milky; not as brilliant as Sri Lanka
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534
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A treatment that uses chemicals to lighten or remove color.
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Bleaching
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548
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Soaking an opal in a hot sugar solution and then in sulfuric acid to darken it and bring out its play-of-color.
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Sugar treatment
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562
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What mine set the quality standard for alexandrite?
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Russia
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576
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Many conditions threaten the ... of the colored stone market.
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stability
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590
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Finest quality andalusite
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yellowish green and orange
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604
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How do yellowish/reddish brown topaz become pink?
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heating
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618
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Gem - trade name "rose topaz"
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pink topaz
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632
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color element - helidor
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iron
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646
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A natural, inorganic substance with a characteristic chemical composition and usually characteristic structure.
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Mineral
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660
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host rock for most beryl
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pegmatites
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674
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color element in green beryl
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primarily iron, some chromium (emerald is primarily chromium or vanadium, with some iron)
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688
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Most common 2 opal treatments
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Sugar treatment and Smoke treatment
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702
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What is assembled opal?
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assembled opal; assembled stone
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716
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What kind of feldspar is plagioclase?
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calcium/sodium feldspar
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730
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what is the most familiar feldspar?
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moonstone
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744
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finest quality - sunstones
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finest - top deep green or red; intense bi-colored sunstones
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758
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... sapphire is readily available, but its color isn’t verymarketable.
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Green
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772
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finest quality - kunzite
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intense pink and intense violetish purple
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786
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You should judge a gemstone’s beauty and value only by comparing it with others of its own (2)
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species or variety
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800
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Some stones reach fine color only in ... others only in …
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large sizes, small sizes
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814
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Describe elbaite tourmaline.
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elbaite - most gem tourmalines; rich in sodium, lithium, aluminum and rarely copper; pegmatites; wide range of colors
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828
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host rock - paraiba?
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pegmatite
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842
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color range red and pink tourmaline?
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purplish red to orange red; low sats appear brown or grayish; strongly sat are worth more
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856
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host rock for peridot?
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baslat
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870
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gem system for spinel?
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cubic crystla system
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884
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What kind of garnet is tsavorite?
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grossularite garnet
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898
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A glittery effect caused by light reflecting from small, flat inclusions within a gemstone.
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Aventurescence
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912
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Direction of single refraction in a doubly refractive gem.
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Optic axis
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926
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color elements (2) for spessartite?
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manganese; traces of iron
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940
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what kind of gem is urarovite?
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garnet
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954
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There are two basic types of gem coral: …(2)
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calcareous coral and conchiolin coral
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968
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color element demantoid
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chromium
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982
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what kind of garnets are African or Mozambique garnets?
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pyrope-almandine garnets
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996
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A synthetic-crystal growth method in which the chemical mixture is melted, then recrystallized.
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Melt process
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1010
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color element in green jadeite
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chromium
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1024
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what color nephrite is best for carving
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white
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1038
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major mining/cutting for calcareous coral
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Mediterranean Sea, near Italian city of Napals; many names are Italian
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1052
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what shell is commonly used for cameos
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helmet shell
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1066
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... is most commonly light pink, but its most valuable colors are intense pink and intense violetish purple.
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Kunzite
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1080
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mining benitoite
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one location - Diablo Mountain Range of San Benito County
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1094
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Turquoise is judged by its (3)
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color, texture, and matrix
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1108
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moldovite is a form of what gem?
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tektite
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1122
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used by vikings as sun filter
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iolite
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1136
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Describe Columbian emerald.
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Colombian - finest emerald color; slightly bluish green with med to med dk tone with strong to vivid sat
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1150
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what is a pearl's most important value factor?
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luster
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1164
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.(2).. are singly refractive, eliminating the need for cutters to consider pleochroism.
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Garnet and spinel
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1178
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Most red garnets, including the popular ... are mixtures of pyrope and almandite.
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rhodolite,
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1192
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How are quartz synthetized?
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hydrothermal
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1206
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Market sector where better-quality gemstones are used in well-finished, moderately priced jewelry pieces.
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Middle market
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1220
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Because of differences in crystal structure, the same ... can cause different colors in different gems.
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transition element
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1234
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Solution processes are generally (2) than melt processes.
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slower and more expensive
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1248
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... is a fairly common pearl treatment.
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Bleaching
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1262
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... deals primarily in high-end rubies and gemstones from other countries.
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Switzerland
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1276
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Kashmir sapphires owe their reputation to a brief period of output in the ...
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1880s
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1290
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... that make an emerald less transparent also make it less valuable.
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Inclusions
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1304
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Due to tanzanite’s strong ... cutters must balance weight retention against quality of face-up color.
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pleochroism,
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1318
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Excellent (2) combined with the sharpest cat’s-eye make chrysoberyl the most-prized chatoyant gem.
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hardness and durability
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1332
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Sources in ... supply the world with most of its large, fine-color peridot.
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Myanmar
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1346
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who first cultured freshwater pearls?
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Masayo Fujita
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1360
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source of tahitian (2)
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French Polynesia and cook islands
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1374
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what happens when amethyst is heat treated
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heat treatment lightens color; WON'T make it darker
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1388
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color range smoky quartz
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light yellowish brown or orange brown to a dark brown almost black
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1402
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most common treatment rose quartz
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irradiation - intensifies color
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1416
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how does chalcedony get it's color?
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stained by solutions rich in metallic salts like iron oxides |
1430
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