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103 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Cultured pearl with any unsightly portion cut or ground off. |
Three-quarter-cut
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8
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Areas of different color in a gem, caused by variations in growth conditions.
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Color zoning
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22
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In many gemstone varieties, ... are more valued than mixed hues.
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pure hues
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36
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Many gemstone species share some of the same hue and ... ranges.
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saturation
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50
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A spherical, often hollow, mineral-lined cavity in rock.
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Geode
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64
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Gems found in the rock that carried them to the surface.
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Primary deposit
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78
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The most valuable jadeite color is the intense green known as …
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Imperial
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92
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A mineral that’s been broken down from a crystalline to a partly amorphous state by emanations from radioactive impurities.
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Metamict
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106
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Degree of darkness or lightness of a color.
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Tone
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120
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China produces the overwhelming majority of the world’s ...
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freshwater cultured pearls
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134
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Small pocket in a gem that’s filled with fluids and, sometimes, gas bubbles and tiny crystals. Usually created by environmental changes during crystal growth.
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Liquid inclusion
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148
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A pearl with one or more grooved or ridged rings all the way around it.
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Circled pearl
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162
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The biggest-selling calibrated colored stone shapes are …(2)
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rounds and ovals
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176
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All pearls display bodycolor, and some also have .___ and ___.. or both.
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overtone or orient
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190
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The relationship of the height of a gem’s crown to the depth of its pavilion, judged by viewing its profile.
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Crown-height to pavilion-depth ratio
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204
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Dividing gem rough into easily handled pieces and removing waste areas.
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Sawing
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218
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You’ll usually see dark areas, or ... through the crown in stones with deep pavilions.
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extinction,
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232
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(2) are important considerations for buyers of treated blue topaz.
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Price and uniformity
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246
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One one-hundredth of a carat (0.01ct.).
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Point
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260
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A general term for a break in a stone.
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Feather
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274
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... often makes boulder opal more durable than other types of opal.
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Matrix backing
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288
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Major sources of both (2 types of opal) are located in Australia.
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black and white opal
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302
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square and flat, like many corundum crystals
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tabular
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316
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Mohs of chrysoberyl, topaz, spinel, emerald, aquamarine
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7 5 to 8 5
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330
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4 gems colored by copper
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tourmaline, turqoise, malachite, blue azurite
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344
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Crystalline minerals are classified into ... crystal systems, depending on the symmetry of their unit cells.
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seven
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358
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A damaged area on a gem, usually near the girdle.
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Chip
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372
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Tiny tension cracks in moonstone that interfere with adularescence and reduce value.
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Centipedes
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386
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Because smoky quartz crystals are often large, inexpensive, and free from flaws, they’re ideal for ...
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gem carvers and sculptors
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400
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What stone was imitated by ancient egyptians?
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lapis
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414
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Finest quality - turquoise
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even, intense, medium blue (some prefer greenish blue); spiderweb turqoise is second in value behind matrix-less
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428
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The reproductive organ that produces eggs in females and sperm in males.
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Gonad
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442
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A simple necklace typically composed of pearls; also, pearls very close to the same size strung without a clasp for wholesale marketing.
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Strand
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456
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What is a type of pyrite; unstable crystalline form of iron and disulphide?
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marcasite
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470
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Two historical sources for ruby
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Mogok and Mong Hsu, Myanmar - most historical ruby source
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484
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Vietnam rubies host rock
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marble
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498
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What is a Ceylon/Sri Lanka ruby?
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Ceylon & Sri Lanka - purplish to pinkest red and med to v ligh in tone; absorbe less light; brighter; more pink sapphires
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512
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Two big treatments for blue sapphire
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heating/lattice diffusion
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526
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finest quality - tanzanite
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pure blue like sapphire; saturation is key value factor
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540
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Exposing a gem to radiation to change or improve its color.
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Irradiation
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554
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color range - iolite
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violetish blue to violet hue
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568
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What era was yellow chrysoberyl popular?
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Victorian estate jewelry
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582
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(3)... are the main attributes of a fine stone.
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Rarity, exceptional color, and large size
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596
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color element - pink, red, violet, and purple topaz
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Chromium
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610
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Where doe the finest topaz come from?
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Brazil
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624
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color element morganite
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manganese
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638
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The basic structural unit of all matter.
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Atom
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652
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gem trade name "red emerald"
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red beryl
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666
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cutting considerations aquamarine
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near-colorless a strong blue in different directions; coincides with orientation that gives most weight
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680
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How does opal form?
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formed in seasonal rains that drench dry ground; showers soak deep ancient underground rock, dissolved silica carried downward
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694
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Two imitations for opal
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John Slocum - turned to imitation "Slocum stone" made of glass; plastic imitation opal
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708
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most widespread mineral on the earth's crust; also most diverse
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feldspar
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722
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To be a gem, a mineral must be (3)
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beautiful, durable, and rare
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736
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What time of gem is non-phenomenal orthoclase?
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feldspar
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750
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Type of species - amazonite
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microcline species
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764
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... is typically the most valued star corundum.
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Star ruby
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778
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What are the two benefits that makes diopside an effective emerald alternative?
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diopside
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792
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If rough is very valuable, cutters often compromise on ... to save weight and avoid loss of money.
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proportions
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806
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Tourmalines are silicates that share 3 elements.
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a group of closely related mineral species that share the same crystal structure, but slightly different chemical and physical properties Tourmaline are silicates that share ALUMINUM, BORON, and FLUORINE (optionally, sodium, lithium, calcium, magnesium, manganese, titanium, copper, iron)
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820
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What tourmaline can rival the green hues of tsavorite garnet and even emerals?
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chrome tourmaline
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834
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What colors green and blue tourmaline?
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iron
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848
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A property of some crystals that causes them to vibrate at a constant frequency when subjected to an electrical currents; uses untwinned crystals
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Piezoelectricity
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862
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inclusions in garnet
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usually free
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876
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imitation (1) spinel
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triplets
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890
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finest quality of tsavorite
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vivid, strongly saturated bluish green to green gems o medium to medium dark tone
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904
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When a gem’s crystal structure splits light into two rays that each travel at a slightly different speed and direction.
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Double refraction
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918
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Process by which a material absorbs some components of visible light and transmits others.
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Selective absorption
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932
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color range almandite
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purple to orangy red
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946
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color range rhodolite?
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dark purplish raspberry red to a light reddish purple; tone med to med dk
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960
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what kind of gem is hessonite?
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garnet
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974
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what kind of gem is malaya?
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garnet
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988
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A process in which finely ground powder is heated, sometimes under pressure, to produce a fine-grained solid material.
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Ceramic process
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1002
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A laboratory creation with essentially the same chemical composition, crystal structure, and properties as its natural counterpart.
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Synthetic gem
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1016
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What does heat treatment do for jadeite?
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Heat treatment (orange and reddish colors from yellow to brown inclusions)
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1030
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mining sea for amber
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Baltic Sea
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1044
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Primary mining for conchiolin coral
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Black coral (Queensland, Australia and Hawaii) Golden Coral (Hawaii, Tasmania, more rare than black)
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1058
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... adularescence is caused by the scattering of light by stacked, alternating mineral layers.
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Moonstone’s
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1072
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what is jet?
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ornamental form of lignite coal that formed with wooden logs washed out to se and sank into mud on the sea floor; logs became impregnated with oil formed by algae and plankton; became less briggle, resulting in jet rather than coal; used ornamentally in prehistoric times; 1861 - was Queen Victoria's mourning gem
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1086
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... is valued for its history and rich blue color.
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Lapis lazuli
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1100
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The southwestern US is the world’s largest producer of turquoise, while China’s Hubai Province is the major source of its …
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top color
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1114
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which obsidians are most popular in jewelry
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usually sheen obsidian or snowflake obsidian are used in jewelry
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1128
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what percentage of emeralds have been treated?
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90%
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1142
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What is a trapiche emerald?
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Trapiche - unusual stone first discovered in 2 Muzo mines; hexagonal pattern; cabochons)
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1156
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what is mother of pearl?
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mother of pearl - the nacreous layer inside a mollusks shell
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1170
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... is extremely rare, so there’s a huge increase in value between small and large fashioned stones.
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Large tsavorite rough
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1184
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In spinel, the higher the ... content, the stronger the red hue.
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chromium
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1198
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A manufacturer who produces faceted stones, cabochons, or carvings.
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Cutter
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1212
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A company or individual that supplies gems to jewelry manufacturers and retailers.
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Wholesaler
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1226
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Only doubly refractive gems can be ...
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pleochroic
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1240
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All treatments—even (2) treatments—should be disclosed as part of every transaction.
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suspected or probable
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1254
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The most valuable ruby colors are (all three)
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red to slightly purplish red with medium to medium-dark tones and vivid saturation
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1268
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The trace elements (2) cause the blue of sapphire.
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iron and titanium
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1282
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... has become a significant source of good- to finequality blue sapphires.
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Madagascar
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1296
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The world’s emeralds are judged against ... finest.
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Colombia’s
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1310
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... with a predominantly blue face-up color are most valuable, so cutters orient the finished stones to display the desirable color.
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Iolites
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1324
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Some well-formed, fine-color tourmaline crystals are more valuable as ... than as fashioned gems.
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mineral specimens
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1338
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What oyster produces akoya pearls?
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Pinctada fucata
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1352
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what percent of freshwater are spherical
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2%
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1366
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two elements in quartz
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silicon and oxygen
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1380
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Describe quality of uruguay and argentina amethyst
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Uruguay and Argentina - strong color zoning, smaller and darker can rival African amethyst;
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1394
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treatments (2) for ametrine
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heat treatment or combo of heat treatment and irradiation
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1408
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primary mining adventurine/quartzite?
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India
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1422
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what is the trans parency of carnelian?
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semi-transparent to opaque |
1436
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