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103 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Cultured pearl with a hole drilled halfway through to permit mounting on a post. |
Half-drilled
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5
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Thousands of tons of rock may be eroded to yield…
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only a few ounces of gem material
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19
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An area of weak saturation in a transparent gemstone’s bodycolor that usually results from the way the gem was cut.
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Window
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33
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Larger stones can appear ... than smaller stones cut from the same rough.
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more saturated
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47
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The surface and outermost layer of the earth.
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Crust
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61
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A section of the earth’s rigid outer crust.
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Plate
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75
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Gem-quality jadeite is more rare and valuable than…
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nephrite
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89
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Jadeite substitutes should not be called “jade,” since only ... are true jades.
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jadeite and nephrite
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103
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Visible face-up color zoning that was planned during the cutting process.
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Intended color zoning
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117
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A saltwater cultured whole pearl grows from a ... implanted in a host mollusk’s gonad.
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mantle-tissue piece and a bead nucleus
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131
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How well a gemstone resists scratches. Usually expressed in terms of the Mohs scale, with diamond the hardest (10) and talc the softest (1).
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Hardness
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145
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Location of a change in crystal growth direction.
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Twinning plane
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159
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A ... is one of a stone dealer’s most useful and versatile tools.
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Leveridge gauge
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173
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The ... of larger pearls is one factor that makes them more valuable.
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rarity
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187
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A gem carving style in which the design, often a woman’s profile, projects slightly from a flat or curved surface.
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Cameo
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201
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Final stage in gem cutting that produces the smoothest possible surface.
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Polishing
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215
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Opaque or ... rough is often cut into cabochons, cameos, intaglios, or beads.
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translucent
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229
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The ... is the world’s major commercial source of imperial and red topaz.
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Ouro Prêto area of Brazil
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243
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Buying agreement where a dealer entrusts merchandise to a client for inspection and approval without requiring immediate payment.
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Memo
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257
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A damaged area on a gem, usually near the girdle.
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Chip
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271
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Play-of-color is produced by the ... with opal’s internal structure of stacked silica spheres.
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interaction of light
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285
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Exceptionally valuable opals are specially cut to display their spectacular …
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play-of-color
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299
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ropaz, iolite, tanzanite (zoisite), chrysoberyl, peridot
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orthorhombic (5)
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313
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toughness of feldspar and topaz
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poor toughness
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327
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6 gems colored by vanadium
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tanzanite, tsavorite garnet (also with chromium), grossularite garnet, green tourmaline, color change garnets, some emeralds
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341
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Natural jadeite enhanced only with a surface coating of wax.
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Type A jadeite
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355
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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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369
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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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383
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Dealers often characterize amethyst from Brazil and Uruguay as ... but both sources can produce gems comparable to African material.
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pale,
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397
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Finest quality - lapis
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violetish blue, medium to dark in tone, highly saturated; no visible calcite; can have gold colored pyrite flecks
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411
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What element lowers value of turquoise?
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iron
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425
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A non-nacreous natural “pearl.” Conchiolin
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Calcareous concretion
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439
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Tissue that encloses an implanted bead nucleus and mantle-tissue piece, or the piece alone, and secretes nacre to form a cultured pearl.
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Pearl sac
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453
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color range - rhodonite
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rosy hue (warm orange-pink to brownish or purplish red with black veins or patches); rarely transparent
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467
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Finest quality - ruby
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vibrant red to slightly purplish hue; vivid saturations
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481
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Host rock Pailin rubies
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basalt
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495
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4 types of ruby synthesis
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flame fusion (cheap); flux (more costly and time consuming); "Pulling"/Dzocharlski (mostly industrial applications); hydrothermal (costly and time consuming; Russian)
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509
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What are the 3 historical mining sources for blue sapphire
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Historically, Kashmir (1881 to 1887), Myanmar, and Sri Lanka
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523
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What kind of gem is tanzanite?
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zoisite
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537
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Using a filler to conceal fractures and improve the apparent clarity of a gem.
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Fracture (fissure) filling
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551
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What gem comes from the greek word for violet?
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iolite
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565
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What is an old name for Cat's Eye?
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"Cymophane" greek for wavelike form; old name for cat's eye
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579
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(3) are important factors for middle-market gems.
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Color, cut, and clarity
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593
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What kind of gem is chiastolite?
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andalusite
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607
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Major source of topaz
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Ouro Preto area of Minas Gerais of Brazil - major source of imperial topaz; still 1-2% output is imperial
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621
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What year did blue topaz hit the market?
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1970s
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635
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primary mining helidor
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Minas Gerias, Brazil
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649
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A natural material composed of masses of mineral crystals of one or more kinds.
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Rock
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663
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color element - aquamarine
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traces of iron; two charge transfer processes work to produce blue; one produces a yellow, the other blue
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677
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How old is Australian opal?
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Mintabie, Australia 400 mill years ago
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691
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What opal is more popular in Japan?
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black
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705
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What is gray base black opal?
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gray background It appears opaque when held up to the light
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719
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What kind of feldspar is oligoclase?
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calcium/sodium feldspar
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733
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Finest quality - moonstone
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colorless, semitransparent to nearly transparent appearance; w/o visible inclusions; vivid blue adularescence; blue sheen
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747
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Mining (2) for sunstones
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Oregon, India
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761
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The trace element ... causes sapphire’s color change.
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vanadium
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775
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What two countries is kunzite popular?
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popular in US and Japan; limited supply, not very expensive
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789
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You shouldn’t use trade terms that imply a gem’s ... if you can’t be sure of its actual source.
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geographic origin
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803
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What gem means"mixed gems" in sinhalese?
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tourmaline
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817
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Describe shorl tourmaline
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schorl - typically black; rich in iron; rarely a gem; mourning jewelry
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831
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finest quality - paraiba?
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blue and violet; more saturated hue and lighter tone
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845
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Chalcedony with curved or angular bands or layers that differ in color and transparency.
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Agate
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859
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treatments for peridot
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NO treatments
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873
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color element violet or grayish violet
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iron
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887
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crystal habit of tsavorite?
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"potato pods"
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901
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A small defect in the atomic structure of a material that can absorb light and give rise to a color.
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Color center
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915
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The flashing rainbow colors in opal.
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Play-of-color
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929
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what is the most widespread garnet?
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almandite
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943
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cut consideration for uvarovite?
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too small to cut; occasionally set in clusters
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957
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Nearly all trade in new elephant ivory has been illegal since the …
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mid-1970s
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971
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finest color - demantoid
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mod strong ot strong sat green of medium to med dark tone
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985
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what color is andradite?
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yellow
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999
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A synthetic-crystal growth method that uses cooling pipes around an interior of melted chemical ingredients.
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Skull melt
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1013
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finest quality jadeite
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vivid hue of green with no hint of gray that looks intense, even from a distance; pure green to slighly bluish green, or slighly yellowish green (compared to emerald, often slighly more yellow and slightly less saturated)
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1027
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what 4 elements in amber?
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carbon, hydrogen, oxygen, traces of sulfer; float in salt water
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1041
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chemistry of conchiolin coral
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principal ingredient is protein, not calcium carbonate
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1055
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Supplies of ... are unpredictable, which results in weak consumer recognition.
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feldspar, spodumene, and diopside
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1069
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What shell is used in tortoise shell?
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shell of the Atlantic Hawksbill Sea Turtle; ornamental use for thousands of years
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1083
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why is fluorite not good for jewelry use?
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4 directions, not good for jewelry use
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1097
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Matrix-free and ... turquoise command the highest prices.
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spiderweb
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1111
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what may have formed moldovite?
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may form when meteorite hits earth; or originated in volcanic eruptions on moon and fell 14 mill years ago
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1125
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color element emerald
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vanadium or chromium, iron increases blue
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1139
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blank |
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1153
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What is a natural pearl |
natural pearl - a pearl that formes w/o human assistance; formes when a foreign object gets inside a pearl bearing mollusk's shell and irritates its soft tissue
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1167
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Gemologists classify garnets by their (2) but many dealers sell garnets on the basis of color or origin. |
chemistry and their properties,
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1181
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Huge numbers of dark-toned, reddish brown, calibrated ... garnets are used in inexpensive, mass-market jewelry. |
pyropealmandite
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1195
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Market sector where averagequality gemstones are used in mass-market jewelry. |
Commercial market
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1209
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A quantity of stones, sometimes of similar size and quality, perhaps from a single mine, but often from various sources, that’s offered for sale together. |
Parcel
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1223
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... is responsible for most blue and yellow gem colors.
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Charge transfer
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1237
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Gemologists play an important role in ensuring that ... becomes the industry standard. |
disclosure
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1251
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Commonly dyed gems include (4)
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cultured pearl, lapis lazuli, chalcedony, and coral
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1265
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The word ... when used alone, typically refers to the blue variety of corundum. |
“sapphire,”
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1279
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blank |
blank |
1293
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Gentle scrubbing with ... the safest way to clean emeralds. |
warm, soapy water is
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1307
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Because ... comes from a single source, changes in supply drastically affect availability and prices. |
tanzanite
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1321
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... pleochroism is so pronounced that its hues are often visible simultaneously through the gem’s crown, creating a mosaic effect. |
Andalusite’s
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1335
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Because of its ... zircon needs care in handling and wear.
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brittleness,
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1349
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when did chinese begin markeing freshwater pearls
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1970s
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1363
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south sea range and average
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8-15 mm; 10-15 mm average
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1377
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Describe quality of S. American amethyst
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S America - Source of lighter colored goods; 75% commercial quality;
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1391
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primary mining smoky quartz
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Cairgorm Mountains of Scotland
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1405
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what kind of quartz crystalite is quartzite? |
microcrystalline quartz
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1419
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what is the trans parency of calcedony? |
semi-transparent to opaque |
1433
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