Key Terms and Review of the Colored Stones GIA course

Question Answer
Lacking a regular Crystal Structure Amorphous
The basic structure unit of all matter Atom
Kinds and relative quantities of atoms that make up a material Chemical Composition
A gem produced by, or derived from, a living organism is A. organic.B. synthetic. C. inorganic. D. manmade. A. Organic
Which of the following is an organic gem?
A. Jade
B. Ruby
C. Amber
D. Tourmaline
C. Amber
A substance that consists of atoms of only one kind is a
A. mineral.
B. unit cell.
C. gem species.
D. chemical element.
D. Chemical Element
A natural, inorganic substance with a characteristic chemical composition and usually characteristic crystal structure is a(n)
A. atom.
B. mineral.
C. synthetic.
D. chemical element
B. Mineral
Most gems are
A. rocks.
B. organic.
C. minerals.
D. synthetic.
C. Minerals
A natural material that’s made up of a mass of one or more kinds of mineral crystals is a
A. rock.
B. group.
C. variety.
D. chemical element.
A. Rock
Which of the following is amorphous?
A. Beryl
B. Amber
C. Garnet
D. Jadeite
B. Amber
A broad gem category based on chemical composition and crystal structure is a
A. rock.
B. group.
C. gem variety.
D. gem species.
D. Gem Species
Which of the following is a gem variety?
A. Beryl
B. Garnet
C. Andradite
D. Demantoid
A. Beryl
Which group does almandine belong to?
A. Spinel
B. Garnet
C. Feldspar
D. Tourmaline
B. Garnet
The world’s largest gem-consuming market is
A. Japan.
B. Europe.
C. Thailand.
D. United States
D. United States
Synthetic gem materials
A. are organic.
B. are not minerals.
C. are usually amorphous.
D. are classified as minerals.
D. Are classified as minerals
To be a gem, a mineral must be beautiful, durable, and
A. rare.
B. colorful.
C. transparent.
D. lightweight.
A. Rare
Many colored stones are mined by
A. large corporations.
B. massive industrial operations.
C. mechanized systems and heavy equipment.
D. independent miners using small-scale mining methods.
D. Independent Miners using small scale methods
Media attention in the 1990s regarding its treatment reduced consumer confidence in
A. spinel.
B. emerald.
C. rhodolite.
D. tanzanite.
B. Emerald
Most gemstones form in the
A. core.
B. mantle.
C. oceanic crust.
D. continental crust.
D. Continental Crust
Rocks altered by heat and pressure are
A. granites.
B. igneous.
C. sedimentary.
D. metamorphic.
D. Metamorphic
Which gem can crystallize in volcanic rock from gasses released by magma?
A. Zircon
B. Red beryl
C. Blue sapphire
D. Vietnamese ruby
B. Red Beryl
Which is a key locality for hydrothermal gems?
A. Tibet
B. Tanzania
C. Ouro Preto, Brazil
D. Mogok, Myanmar
C. Ouro Preto, Brazil
Which gem forms by metamorphism?
A. Opal
B. Red beryl
C. Turquoise
D. Tanzanite
D. Tanzanite
Heat and pressure transform limestone into
A. opal.
B. quartz.
C. granite.
D. marble.
D. Marble
A deposit where gems are found in the rock that carried them to the earth’s surface is called
A. primary.
B. substitute.
C. secondary.
D. concentrated.
C. Secondary
Which type of deposit is usually the most profitable for colored stone mining?
A. Primary
B. Hard rock
C. Secondary
D. Metamorphic
C. Secondary
Which is a deposit where gems eroded from the source rock and remained in place nearby?
A. Eluvial
B. Primary
C. Alluvial
D. Metamorphic
A. Eluvial
Which is a workable alluvial deposit of gem minerals with economic potential?
A. Vein
B. Geode
C. Placer
D. Primary
C. Placer
Kunzite is most often found in association with
A. sapphire in lava.
B. moonstone in basalt.
C. tourmaline and beryl in pegmatite.
D. imperial topaz in hydrothermal veins.
C. Tourmaline and Beryl in pegmatite
Myanmar’s famous Mogok ruby deposits were formed by
A. sedimentary processes.
B. regional metamorphism.
C. gas crystallization from molten lava.
D. mineral-rich solutions close to the earth’s surface.
B. Regional Metamorphism
Pegmatite gems are rich in volatile elements like
A. chromium and vanadium.
B. nickel, copper, and cobalt.
C. beryllium, boron, and lithium.
D. iron, magnesium, and titanium
C. Beryllium, Boron, and Lithium
Most of the gems in Tanzania’s Umba River Valley are found in
A. geodes.
B. placer deposits.
C. primary deposits.
D. hydrothermal gem deposits.
B. Placer Deposits
Emeralds are rarely found in placer deposits because they’re
A. too soft.
B. too rare.
C. chemically unstable.
D. unable to withstand much abrasion.
D. Unable to withstand much abrasion
A workable alluvial deposit of gem minerals with
economic potential is a
A mass of tiny, randomly oriented crystals is called an _____ Aggregate
Rock formed by the crystallization of
molten material is called _______ rock
A deposit where gems are eroded
from their source rock, then transported away from
the source are ______
A unit cell defines a mineral’s
A. size.
B. habit.
C. shape.
D. basic identity.
D. Basic Identity
If a crystal grows in a flux that is highly saturated with the necessary elements, it tends to be
A. large.
B. small.
C. terminated.
D. well formed
B. Small
Which aggregate’s crystals are visible only with magnification greater than a standard gemological microscope’s?
A. Mesocrystalline
B. Megacrystalline
C. Microcrystalline
D. Cryptocrystalline
D. Cryptocrystalline
Which is classified in the orthorhombic crystal system?
A. Beryl
B. Topaz
C. Garnet
D. Corundum
B. Topaz
Which element causes red in ruby and green in emerald?
A. Calcium
B. Potassium
C. Chromium
D. Magnesium
C. Chromium
Which type of twinning looks as if two crystal halves are mirror images?
A. Cyclic
B. Contact
C. Penetration
D. Polysynthetic
B. Contact
Needles of actinolite found in emerald are classified as
A. cleavages.
B. inclusions.
C. penetration twins.
D. impurity elements.
B. Inclusions
A two-phase inclusion is a cavity in a gem that’s typically filled with a
A. pair of liquids.
B. gas and a solid.
C. liquid and a gas.
D. liquid and a solid.
C. Liquid and a gas
Atoms in a gem that are not part of its essential chemical composition are
A. unit cells.
B. inclusions.
C. trace elements.
D. chemical compounds.
C. Trace Elements
The trace elements that cause corundum’s blue are
A. iron and titanium.
B. chromium and iron.
C. aluminum and oxygen.
D. aluminum and chromium.
A. Iron and Titanium
An object’s weight in relation to its size is called its
A. density.
B. carat total.
C. atomic index.
D. specific gravity
A. Density
Which gems are cryptocrystalline aggregates?
A. Opal and amethyst
B. Nephrite and jadeite
C. Sugilite and lapis lazuli
D. Chalcedony and turquoise
D. Chalcedony and Turquoise
Rough spinel often occurs as
A. twinned crystals.
B. tall, columnar crystals.
C. microcrystalline aggregates.
D. flattened cleavage fragments.
A. Twinned Crystals
Many fashioned rubies have shallow proportions because they’re cut from
A. flat crystals.
B. tall, columnar crystals.
C. heavily included rough.
D. flattened cleavage pieces.
A. Flat Crystals
The pattern of dark vertical lines or bands shown by certain gems when viewed through a spectroscope is called
A. refraction.
B. dispersion.
C. pleochroism.
D. absorption spectrum.
D. Absorption Spectrum
Which element does chromium substitute for to cause ruby’s red?
A. Silicon
B. Titanium
C. Beryllium
D. Aluminum
D. Alluminum
A gem colored by an element that’s part of its basic chemistry is called
A. other-colored.
B. allochromatic.
C. many-colored.
D. idiochromatic.
D. Idiochromatic
Which element causes the color of both almandine and peridot?
A. Iron
B. Cobalt
C. Titanium
D. Chromium
A. Iron
Process where electrons that selectively absorb light are passed back and forth between neighboring impurity ions is called
A. diffraction.
B. interference.
C. charge transfer.
D. intervalence charge transfer.
C. Charge Transfer
Which components of a transition element’s atoms can produce color in gems?
A. Nuclei
B. Protons
C. Neutrons
D. Electrons
D. Electrons
Which element causes the finest reds and greens in gemstones?
A. Iron
B. Cobalt
C. Chromium
D. Magnesium
C. Chromium
Which transition element causes a greater variety of gem colors than any other?
A. Iron
B. Cobalt
C. Vanadium
D. Chromium
A. Iron
In many blue sapphires, the intervalence charge transfer that causes the color is between
A. iron and iron.
B. iron and titanium.
C. chromium and iron.
D. oxygen and oxygen.
B. Iron and Titanium
When a gem’s crystal structure splits light into two rays that each travel at a slightly different speed and direction, it’s called
A. diffraction.
B. interference.
C. single refraction.
D. double refraction.
D. Double Refraction
What is the only type of gem that can show pleochroism?
A. Faceted
B. Phenomenal
C. Singly refractive
D. Doubly refractive
D. Doubly Refractive
Which gem can show three pleochroic colors?
A. Iolite
B. Ruby
C. Sapphire
D. Tourmaline
A. Iolite
Which phenomenon is a broad color flash?
A. Orient
B. Iridescence
C. Change-of-color
D. Labradorescence
D. Labradorescence
Adularescence is caused by
A. dispersion.
B. scattering of light.
C. selective absorption.
D. reflections from inclusions.
B. Scattering of Light
The best-known and most valuable chatoyant gem is cat’s-eye
A. zircon.
B. quartz.
C. tourmaline.
D. chrysoberyl.
D. Chrysoberyl
A laboratory-created gem with essentially the same chemical composition, crystal structure, and properties as its natural counterpart is a(n)
A. fake.
B. synthetic.
C. duplicate.
D. imitation.
B. Synthetic
The two main types of processes for synthetic gem production are melt and
A. pulling.
B. solution.
C. flame fusion.
D. floating zone.
B. Solution
Low cost and high volume characterize which process?
A. Pulling
B. Flux growth
C. Flame fusion
D. Hydrothermal growth
C. Flame Fusion
Which synthetic process developed rapidly due to laser research in the 1960s?
A. Pulling
B. Skull melt
C. Flame fusion
D. Spontaneous nucleation
A. Pulling
Which process uses a heating unit to pass over a rotating solid rod of chemicals until it forms a synthetic crystal?
A. Skull melt
B. Flux growth
C. Flame fusion
D. Floating zone
D. Floating Zone
Which process dissolves nutrients in chemicals to form synthetic crystals?
A. Ceramic
B. Flux growth
C. Floating zone
D. Hydrothermal growth
B. Flux Growth
The crucibles that work best for flux growth are made of
A. gold.
B. silver.
C. titanium.
D. platinum
D. Platinum
The hydrothermal growth process is the only method used to produce which synthetic gem?
A. Opal
B. Quartz
C. Alexandrite
D. Green chrysoberyl
B. Quartz
Which synthetic process uses an autoclave?
A. Pulling
B. Skull melt
C. Flux growth
D. Hydrothermal growth
D. Hydrothermal Growth
Synthetic opal is grown using microscopic silica spheres that are produced by
A. pulling.
B. sublimation.
C. precipitation.
D. spontaneous nucleation.
C. Precipitation
Which process involves heating finely ground powder, sometimes under pressure, to produce a fine-grained solid material?
A. Ceramic
B. Sublimation
C. Precipitation
D. Spontaneous nucleation
A. Ceramic
Synthetic turquoise is most likely produced by which process?
A. Pulling
B. Ceramic
C. Sublimation
D. Floating zone
B. Ceramic
The flux used in the flux process is a solid material that, when molten,
A. dissolves other materials.
B. acts as a pattern for crystal growth.
C. helps prevent the formation of inclusions.
D. produces straight growth patterns in synthetic gems.
A Dissolves other materials
The hydrothermal synthetic process requires a
A. chemical flux and plat. crucible.
B. high-temp flame and powdered feed chemicals.
C. rod of ingredients and a high-temperature heating coil.
D. pressurized steel container and chemical ingredients.
D. Pressurized steel container and chemical ingredients
A snakeskin structural pattern is typical of
A. synthetic opal.
B. imitation lapis lazuli.
C. flame-fusion synthetics.
D. hydrothermal synthetic quartz.
A. Synthetic opal
Which of these is considered a gem treatment?
A. Cutting
B. Polishing
C. Fashioning
D. Fracture filling
D. Fracture Filling
Written information on dyeing gems dates back to about
A. 200 BC.
B. 100 AD.
C. 300 AD.
D. 700 AD
A. 200 BC
Which gem is commonly heat-treated?
A. Iolite
B. Amber
C. Tsavorite
D. Rhodolite
B. Amber
Heat can lighten amethyst’s purple by
A. dissolving rutile.
B. affecting titanium impurities.
C. affecting chromium impurities.
D. causing changes in color centers.
D. Causing changes to color centers
Creating asterism with heat treatment is most common in
A. natural ruby.
B. natural sapphire.
C. synthetic corundum.
D. natural fancy sapphire.
C. Synthetic Corundum
What coloring agents do treaters use during lattice diffusion to create a shallow layer of blue color in corundum?
A. Cobalt and iron oxide
B. Chromium and iron oxide
C. Titanium oxide and iron oxide
D. Titanium oxide and chromium
C. Titanium and Iron Oxides
How deep is the color layer that lattice diffusion with titanium or chromium creates in corundum?
A. 0.01 mm to 0.50 mm
B. 0.50 mm to 1.00 mm
C. 1.00 mm to 1.50 mm
D. 1.50 mm to 2.00 mm
A. 0.01 mm to 0.50 mm
What agent can create a shallow layer of asterism when it’s introduced below the surface of a corundum cabochon by lattice diffusion?
A. Iron oxide
B. Chromium
C. Titanium oxide
D. Aluminum oxide
C. Titanium oxide
For effective clarity enhancement, the material used to fill a gem’s fractures must have nearly the same
A. color as the gem.
B. density as the gem.
C. hardness as the gem.
D. refractive index as the gem.
D. Refractive Index as the gem
After irradiation, which gem’s color is stable under normal wearing conditions?
A. Golden beryl
B. Orange sapphire
C. Yellow sapphire
D. Green spodumene
A. Golden Beryl
Jadeite is often
A. irradiated.
B. irradiated and annealed.
C. surface-diffusion treated.
D. bleached and polymer impregnated.
D. Bleached and Polymer impregnated
The Zachery method is a treatment applied to
A. jadeite.
B. turquoise.
C. lapis lazuli.
D. cultured pearl.
B. Turquoise
Heat treatment in a reducing environment
A. creates golden color in beryl.
B. lightens blue color in sapphire.
C. deepens blue color in sapphire.
D. deepens red color in tourmaline.
C. Deepens blue color in sapphire
Quartz or topaz with a thin layer of gold deposited on the surface is known as
A. lemon.
B. smoky.
C. Madeira.
D. aqua aura.
B. Aqua Aura
Treaters use sugar treatment to enhance
A. opal.
B. amber.
C. jadeite.
D. lapis lazuli.
A. Opal
What is Myanmar’s most important gem export?
A. Ruby
B. Spinel
C. Jadeite
D. Sapphire
A. Ruby
Which location produces the majority of rubies that end up in mass-produced jewelry?
A. Pailin
B. Mogok
C. Bo Phloi
D. Mong Hsu
D. Mong Hsu
Which trade term describes a mixture of gem qualities that represents unsorted production from a particular mine?
A. Mine run
B. Mine grade
C. Mine mixture
D. Mine assortment
A. Mine Run
Which term describes a specific rough gemstone quality range, usually determined by color, size, clarity, and price?
A. Grade
B. Mine lot
C. Mine run
D. Mine production
A. Grade
Where is rough from Mogok brought into Thailand?
A. Pailin
B. Mae Sai
C. Mae Sot
D. Bo Phloi
C. Mae Sot
Where is rough from Mong Hsu brought into Thailand?
A. Pailin
B. Mae Sai
C. Mae Sot
D. Bo Phloi
B. Mae Sai
In mining terms, the theft of a mine’s production by its workers is known as
A. picking.
B. cobbing.
C. low grading.
D. high grading.
D. High Grading
Which of the following is a quantity of stones, sometimes of similar size and quality, from a single mine or from many different sources?
A. Parcel
B. Mine lot
C. Mine run
D. Production run
A. Parcel
Which of these is a cutting center for colored stones in Thailand?
A. Pailin
B. Mogok
C. Mong Hsu
D. Chantaburi
D. Chantaburi
Materials cut free-size are usually
A. synthetics.
B. manmade imitations.
C. large, important stones.
D. commercial-quality gems.
C. Large, important stones
Gemstone sizes cut to fit standard mountings are known as
A. free sizes.
B. designer cuts.
C. industry sizes.
D. calibrated sizes.
D. Calibrated sizes
The market sector where better-quality gemstones are used in well-finished, moderately priced jewelry is known as the
A. mass market.
B. middle market.
C. high-end market.
D. commercial market.
B. Middle Market
Which term describes a random sample from a parcel of gemstones, often used to assess the parcel’s overall quality?
A. Cut
B. Lot
C. Pick
D. Grade
A. Cut
Which of the following is a price for buying an entire parcel of gems, or a substantial part of it?
A. Lot price
B. Cut price
C. Pick price
D. Grade price
A. Lot Price
Which of the following is a premium price for selecting stones from a parcel?
A. Lot price
B. Pick price
C. Grade price
D. Parcel price
B. Pick Price
Which gemstone occurs in almost every color?
A. Peridot
B. Turquoise
C. Tourmaline
D. Lapis lazuli
C. Tourmaline
The first impression of an object’s basic color is its
A. hue.
B. tone.
C. saturation.
D. bodycolor.
A. Hue
Generally, cool-colored hues with low saturation look
A. bluish.
B. grayish.
C. brownish.
D. yellowish.
B. Grayish
Use trade terms that imply geographic origin only if the
A. color is typical of the source.
B. gem’s actual source is known.
C. clarity is typical of the source.
D. color and clarity are typical of the source.
B. Gem's actual source is known
Which trade term describes certain tourmalines?
A. “Paraiba”
B. “Kashmir”
C. “Sandawana”
D. “Mozambique”
A. Paraiba
Which abbreviation does the GIA Colored Stone Grading System use for a slightly purplish red hue?
A. pR
B. spR
C. slpR
D. stpR
C. slpR
In practice, what GIA Colored Stone Grading tone levels apply to grading transparent colored stones?
A. 1 through 11
B. 2 through 6
C. 2 through 8
D. 2 through 10
C. 2 through 8
A see-through area in a transparent gemstone’s bodycolor that usually results from the way the gem was cut is called
A. extinction.
B. a window.
C. color zoning.
D. color banding.
B. A window
A window usually differs from the rest of the stone in
A. hue.
B. tone.
C. saturation.
D. hue and tone
C. Saturation
Extinction results from
A. mixed cuts.
B. deep pavilions.
C. shallow proportions.
D. excellent proportions.
B. Deep Pavilions
The color of the background for grading a colored stone should be
A. dark.
B. bright.
C. neutral.
D. the same hue as the gem.
C. Neutral
What type of lighting is best for grading color in a colored stone?
A. Halogen
B. Incandescent
C. High red content
D. Daylight-equivalent fluorescent
D. Daylight-equivalent flourescent
Higher levels of saturation are usually found in stones with
A. dark to very dark tone.
B. very light to light tone.
C. very light to medium tone.
D. medium to medium-dark tone
D. Medium to medium-dark tone
What two coloring agents are usually responsible for color change in gemstones?
A. Copper and iron
B. Iron and titanium
C. Cobalt and titanium
D. Chromium and vanadium
D. Chromium and Vanadium
Emission of visible light by a material when it’s exposed to invisible ultraviolet radiation is
A. pleochroism.
B. color zoning.
C. fluorescence.
D. color change.
C. Fluorescence
Which type of rough is usually faceted?
A. Opaque
B. Translucent
C. Transparent
D. Highly included
C. Transparent
To retain as much weight as possible from rare, high-quality rough, cutters would most likely vary
A. finish.
B. polish.
C. proportions.
D. facet placement.
C. Proportions
Removing heavily included sections from gemstone rough by carefully tapping it with a small hammer is known as
A. cabbing.
B. cobbing.
C. grinding.
D. polishing.
B. Cobbing
Rough that’s ground to the approximate shape of the finished stone is called
A. preform.
B. crown cut.
C. pavilion cut.
D. ground rough.
A. Preform
Which is most likely to undergo cobbing?
A. Fine-quality ruby rough
B. Fine-quality emerald rough
C. Fine-quality alexandrite rough
D. Commercial-quality amethyst rough
D. Commercial-quality amethyst rough
Which cutting stage has the greatest impact on the value of the finished gem?
A. Sawing
B. Cobbing
C. Polishing
D. Preforming
D. Preforming
Which colored stone variety has cutting challenges due to vulnerable cleavage planes?
A. Tsavorite
B. Tanzanite
C. Rhodolite
D. Alexandrite
B. Tanzanite
Translucent to opaque rough is often cut into a
A. step cut.
B. buff-top.
C. cabochon.
D. brilliant cut.
C. Cabochon
Which is a carved design that projects slightly from a flat or curved surface?
A. Cameo
B. Intaglio
C. Buff-top
D. Sugarloaf
A. Cameo
Colored stones cut flat with shallow pavilions usually have areas of lower color intensity called
A. windows.
B. brilliance.
C. extinction.
D. dispersion.
A. Windows
A cutter can darken the color of a pale stone by cutting a
A. large table.
B. deep pavilion.
C. shallow crown.
D. shallow pavilion.
B. Deep pavilion
To judge brilliance, view the stone
A. face-up.
B. in profile.
C. table-down.
D. pavilion-up.
A. Face up
The purpose of most variations in a colored stone’s face-up outline is to
A. save weight.
B. reduce extinction.
C. increase brilliance.
D. reduce windowing.
A. Save weight
Excessive bulge on a step cut
A. adds weight.
B. adds beauty.
C. increases brilliance.
D. makes mounting easier.
A. Adds weight
Colored stones that rate “fair” for brilliance have
A. less than 25 percent brilliance.
B. between 25 and 40 percent brilliance.
C. between 40 and 60 percent brilliance.
D. between 60 and 75 percent brilliance.
B. between 25 to 40 percent
A characteristic or irregularity confined to the surface of a polished gemstone is a(n)
A. cavity.
B. blemish.
C. fracture.
D. inclusion.
B. Blemish
An angular, hollow space that resembles a mineral inclusion is called a
A. needle.
B. crystal.
C. pinpoint.
D. negative crystal.
D. Negative Crystal
A general term for a break in a stone is
A. chip.
B. cavity.
C. feather.
D. fingerprint.
C. Feather
An inclusion with the most negative impact on a colored stone’s clarity would be located
A. near the girdle.
B. under the table.
C. under a crown facet.
D. under a crown main.
In which colored stone clarity type are the gems usually eye-clean?
A. Type I
B. Type II
C. Type III
D. Type IV
A. Type I
The highest clarity grade for colored stones is
A. flawless.
B. eye-clean.
C. internally flawless.
D. very very slightly included.
B. Eye-clean
The term “silk” describes
A. intersecting fractures.
B. intersecting scratches.
C. a group of included crystals.
D. a group of fine, needle-like inclusions.
D. Group of fine, needle-like inclusions
Fingerprints are
A. pits.
B. fractures.
C. blemishes.
D. partially healed fracture planes.
D. Partially healed fracture planes
Which of these gems is classified as Type III?
A. Ruby
B. Topaz
C. Emerald
D. Chrysoberyl
C. Emerald
In which of the following colored stone clarity grades do the definitions vary for each clarity type?
A. Eye-clean
B. Heavily included
C. Severely included
D. Moderately included
1. Which of these characteristics could have the greatest impact on a gem’s marketability?
A. A cavity on its pavilion
B. A large, unhealed feather
C. A small, dark crystal under its crown facets
D. A low-relief liquid inclusion under its table
B. A large, unhealed feather
Gems that are usually eye-clean include
A. peridot, spinel, and quartz.
B. ruby, alexandrite, and andalusite.
C. spodumene, yellow beryl, and aquamarine.
D. red beryl, emerald, and watermelon tourmaline.
C. Spodumene, yellow beryl, and aquamarine
Inclusions are important to gemologists because they
A. usually increase a gem’s value.
B. usually create attractive phenomena.
C. always identify a gem’s geographic origin.
D. can help separate natural from synthetic gems
D. Can help separate natural from synthetic gems
Growth zoning in a colored stone is evidence of
A. fashioning.
B. heat treatment.
C. crystal growth.
D. fracture filling.
C. Crystal Growth
Two factors that determine an inclusion’s impact on a gem’s value are
A. size and shape.
B. position and relief.
C. location and shape.
D. crystal system and size.
B. Position and relief
A gem’s price divided by its carat weight is called
A. lot price.
B. parcel price.
C. per-carat price.
D. total gem price.
C. Per-carat price
The international unit of measurement for gem weight is the
A. gram.
B. ounce.
C. troy ounce.
D. metric carat.
D. Metric carat
Individual stone prices are referred to as
A. unit prices.
B. parcel prices.
C. per-carat prices.
D. total gem weight prices.
A. Unit Prices
How many points are in a metric carat?
A. 10
B. 50
C. 100
D. 1000
C. 100
A metric carat equals
A. 0.20 gram.
B. 0.50 gram.
C. 1 gram.
D. 10 grams.
A. 0.20 gram
Most colored stones are sold
A. by size.
B. by shape.
C. per piece.
D. by weight.
D. By weight
What category of colored stone is often sold per piece?
A. Large
B. Free-size
C. Expensive
D. Small, inexpensive
D. Small, inexpensive
Sieves are most useful for sorting round gems with diameters
A. 3 mm and below.
B. 8 mm and below.
C. 15 mm and below.
D. 20 mm and below.
A. 3mm and below
When you first start to count a large pile of small gems, it’s best to separate them into groups of
A. 5.
B. 8.
C. 17.
D. 30.
A. 5
The color of a sorting pad should be
A. dark.
B. vivid.
C. neutral.
D. intense.
C. Neutral
Colored stones with higher values usually have
A. dark to very dark tone and strong saturation.
B. very light to light tone and strong saturation.
C. very light to medium tone and strong saturation.
D. medium to medium-dark tone and vivid saturation.
D. Medium to medium-dark tone and vivid saturation
If an emerald weighs 3.50 carats and the stone’s cost is $10,500.00, what is its per-carat price?
A. $300.00
B. $367.50
C. $3,000.00
D. $36,750.00
C. $3,000
If a parcel of sapphires weighs 382.00 cts. and the per-carat price is $80.00, what is the total cost of the parcel?
A. $477.50
B. $3,560.00
C. $4,775.00
D. $30,560.00
D. $30,560
If a parcel of amethysts contains 1,000 stones and weighs a total of 1,542.00 cts. with a cost of $0.75 per carat, what is the unit price?
A. $1.16
B. $11.56
C. $115.65
D. $1,156.50
A. $1.16
What is the cost of a ruby that weighs 5.76 cts. and has a per-carat price of $5,500.00?
A. $954.86
B. $3,168.00
C. $9,548.60
D. $31,680.00
D. $31,680
In ancient Sanskrit, ruby is called ratnaraj or
A. “red fire.”
B. “eternal flame.”
C. “endless flame.”
D. “king of precious stones.”
D. "King of precious stones"
The most valuable tone and saturation for ruby are
A. dark tone and strong saturation.
B. medium tone and strong saturation.
C. very dark tone and vivid saturation.
D. medium to medium-dark tone and vivid saturation.
D. Medium to medium-dark tone and vivid saturation
Corundum can form only in an environment that’s low in
A. silicon.
B. oxygen.
C. aluminum.
D. chromium.
A. Silicon
Rubies that come from marble deposits are typically low in
A. iron.
B. oxygen.
C. chromium.
D. aluminum
A. Iron
Ruby deposits in Thailand and Cambodia are associated with
A. marble.
B. granite.
C. limestone.
D. alkali-basalt.
D. Alkali-basalt
Heat-treating Mong Hsu rubies
A. darkens the color.
B. creates brown overtones.
C. creates dark centers or cores.
D. eliminates dark centers or cores.
D. Eliminates dark centers or cores
The world’s largest corundum marketing center is
A. Burma.
B. Vietnam.
C. Thailand.
D. Sri Lanka.
C. Thailand
Switzerland exports rubies that are primarily
A. low end.
B. high end.
C. cabochon grade.
D. commercial quality
B. High end
What location has supplied the world with most commercial-quality rubies since 1991?
A. Mogok
B. Bo Rai
C. Mong Hsu
D. Umba River Valley
C. Mong Hsu
In the early 1980s, the major source for rubies was
A. Kenya.
B. Burma.
C. Vietnam.
D. Thailand.
D. Thailand
Compared to Myanmar rubies, most Thai rubies tend to be
A. darker.
B. lighter.
C. higher quality.
D. more saturated.
A. Darker
Rubies from Pailin, Cambodia, are similar to those from
A. Vietnam.
B. Thailand.
C. Myanmar.
D. Sri Lanka.
B. Thailand
Vietnamese rubies originate in
A. basalt.
B. marble.
C. granite.
D. limestone.
B. Marble
Where are the Penny Lane and John Saul mines located?
A. Kenya
B. Thailand
C. Tanzania
D. Madagascar
A. Kenya
Newly discovered ruby deposits at Vatomandry and Andilamena are in what country?
A. Kenya
B. Malawi
C. Tanzania
D. Madagascar
D. Madagascar
The most highly valued hues of blue sapphire are
A. blue to green-blue.
B. blue to violet-blue.
C. blue to greenish blue.
D. blue to violetish blue.
D. Blue to violetish blue
What trace elements cause blue sapphire’s color?
A. Titanium and iron
B. Chromium and iron
C. Manganese and iron
D. Magnesium and iron
A. Titanium and Iron
Blue sapphires that originate in basaltic rock generally have
A. low iron content.
B. high iron content.
C. high chromium content.
D. high manganese content.
B. High Iron Content
Milky, grayish, or brownish corundum that can be treated to a fine blue color is called
A. dhun.
B. geuda.
C. cornflower.
D. parti-colored.
B. Geuda
Finer-quality Kashmir blue sapphires typically show
A. light tones.
B. inky colors.
C. very dark tones.
D. velvety appearance.
D. Velvety appearance
Australian blue sapphire color is often described as
A. inky.
B. velvety.
C. royal blue.
D. cornflower blue.
A. Inky
Blue sapphire’s most common crystal habit is
A. an octahedron.
B. a twinned octahedron.
C. a long hexagonal prism.
D. a spindle-shaped hexagonal pyramid or bipyramid
D. Spindle-shaped hexagonal pyramid or bipyramid
Blue sapphire’s pleochroic colors are typically
A. green and blue.
B. purple and blue.
C. green-blue and violet.
D. slightly greenish blue and slightly violetish blue
D. Slightly greenish blue to slightly violetish blue
Most fine sapphires over 100 cts. come from
A. Montana.
B. Australia.
C. Sri Lanka.
D. Cambodia.
C. Sri Lanka
Which of the following sources emerged in the 1990s as a significant source of good- to fine-quality sapphire?
A. Kashmir
B. Australia
C. Sri Lanka
D. Madagascar
D. Madagascar
Of these characteristics, which one is most commonly seen in sapphire?
A. Color zoning
B. Etch tunnels
C. Horsetail inclusions
D. Three-phase inclusions
A. Color Zoning
The sapphire market level supplied by Switzerland is
A. upper.
B. lower.
C. middle.
D. commercial.
A. Upper
Kashmir’s most important sapphire production period was from
A. 1789 to 1802.
B. 1840 to 1851.
C. 1881 to 1887.
D. 1901 to 1936.
C. 1881 to 1887
When did Madagascar become a significant source of blue sapphire?
A. 1950s
B. 1960s
C. 1970s
D. 1990s
D. 1990s
Which location supplies sapphires that are most likely not heat-treated?
A. Rock Creek
B. Yogo Gulch
C. Missouri River
D. Dry Cottonwood Creek
B. Yogo Gulch
The name padparadscha means
A. guava.
B. salmon.
C. Sri Lanka.
D. lotus flower.
D. Lotus Flower
What’s a common trade name for intensely saturated, light to medium pinkish orange to orange-pink sapphires?
A. Thai
B. Umba
C. Tunduru
D. Padparadscha
D. Padparadsha
Color-change sapphire typically changes from blue or violet to
A. orange.
B. bluish green.
C. greenish blue.
D. reddish purple.
D. Reddish Purple
Sapphire’s color change is caused by
A. iron.
B. titanium.
C. vanadium.
D. chromium.
C. Vanadium
The most common number of rays in star corundum is
A. 4.
B. 6.
C. 10.
D. 12.
B. 6
Asterism in black star sapphire is caused by
A. tubes.
B. hematite.
C. twinning planes.
D. copper platelets.
B. Hematite
The best-quality star corundum is
A. opaque.
B. translucent.
C. transparent.
D. semi-transparent.
D. Semi-transparent
Which is the most prized bodycolor in star corundum?
A. Red
B. Black
C. Purple
D. Golden
A. Red
What causes the pink color of corundum?
A. Iron
B. Copper
C. Chromium
D. Manganese
C. Chromium
Which fancy sapphire hue regularly commands top prices?
A. Pink
B. Green
C. Purple
D. Yellow
A. Pink
Green sapphire is
A. very rare.
B. very marketable.
C. highly saturated.
D. readily available.
D. Readily available
Which color of star sapphire is usually cut shallow due to parting?
A. Pink
B. Blue
C. Black
D. Yellow
C. Black
A major source of black star sapphire is
A. Tanzania.
B. Australia.
C. Myanmar.
D. Sri Lanka.
B. Australia
Fancy sapphires from Montana tend to be
A. intense.
B. very dark.
C. light in tone.
D. highly saturated.
C. Light in tone
The first flame-fusion star rubies were produced in the
A. 1880s.
B. 1920s.
C. 1930s.
D. 1940s.
D. 1940s
The most desirable emerald hues are
A. blue-green to green.
B. bluish green to green.
C. yellow-green to green.
D. yellowish green to green.
B. Bluish green to green
Which element increases the amount of blue in an emerald’s color?
A. Iron
B. Titanium
C. Vanadium
D. Chromium
A. Iron
The trade term “Zambian” describes emeralds with
A. lighter tone than “Brazilian.”
B. lighter tone than “Colombian.”
C. more bluish color and darker tone than “Colombian.”
D. less bluish color and more saturation than “Colombian.”
C. More bluish color and darker tone than "Colombian".
Brazilian emeralds are mined from
A. limestone.
B. hydrothermal deposits.
C. solidified volcanic magma.
D. pegmatites, where they intersect with schists.
D. Pegmatites, where they intersect with schists.
To emphasize the most desirable color, cutters orient a fashioned emerald with its table
A. parallel to the crystal length.
B. perpendicular to the crystal length.
C. at a 45° angle to the crystal length.
D. at a 30° angle to the crystal length.
B. Perpendicular to the crystal length
What’s the estimated percentage of fashioned emeralds that contain filled fractures?
A. 10
B. 30
C. 60
D. 90 or more
D. 90 or more
Which two countries account for about 75 percent of emerald purchases worldwide?
A. US and Japan
B. China and Japan
C. US and Germany
D. Germany and Japan
A. US and Japan
The four major emerald sources are Colombia, Zambia, Brazil, and
A. Russia.
B. Pakistan.
C. Myanmar.
D. Zimbabwe
D. Zimbabwe
One of Colombia’s traditional emerald mines is called
A. Goias.
B. Bahia.
C. Coscuez.
D. Minas Gerais.
C. Coscuez
Compared to emeralds from other sources, emeralds from African mines
A. are very large.
B. are less saturated in color.
C. generally contain more fractures.
D. generally contain fewer fractures.
D. Generally contain fewer fractures
Trapiche emeralds were first discovered in
A. Muzo.
B. Bahia.
C. La Pita.
D. Kafubu.
A. Muzo
Emeralds were discovered in Zambia in the
A. 1890s.
B. 1930s.
C. 1950s.
D. 1970s.
B. 1930s
Zambian emerald crystals are typically
A. well formed.
B. flat and tabular.
C. irregular in shape.
D. long and prismatic.
C. Irregular in Shape
The Sandawana emerald mine was discovered in the
A. 1920s.
B. 1950s.
C. 1970s.
D. 1980s.
B. 1950s
Who produced a hydrothermal synthetic emerald layer over faceted beryl seeds in the 1960s?
A. Linde
B. Gilson
C. Chatham
D. Lechleitner
D. Lechleitner
Pearl is
A. a crystal.
B. a mineral.
C. an organic gem.
D. an inorganic gem.
C. Organic gem
Aragonite is a crystallized form of
A. silica.
B. nacre.
C. conchiolin.
D. calcium carbonate.
D. Calcium Carbonate
By what date had Kokichi Mikimoto begun culturing whole pearls?
A. 1908
B. 1920
C. 1932
D. 1954
A. 1908
Which industry directly contributed to the decline of the natural pearl industry?
A. Oil
B. Textiles
C. Tourism
D. Electronics
A. Oil
The first South Sea cultured pearl farm was founded in which country?
A. Japan
B. Tahiti
C. China
D. Australia
D. Australia
Saltwater whole cultured pearls grow from a
A. parasite.
B. bead nucleus only.
C. mantle-tissue piece only.
D. mantle-tissue piece and a bead nucleus.
D. Mantle-tissue piece and a bead nucleus
The great majority of freshwater whole cultured pearls grow from a
A. parasite.
B. bead nucleus only.
C. mantle-tissue piece only.
D. mantle-tissue piece and a bead nucleus.
C. Mantle-tissue piece only
In the early 1990s, oysters in many important Japanese cultured pearl farming areas began to
A. multiply rapidly.
B. produce larger pearls.
C. stabilize their numbers.
D. die off in massive numbers.
D. Die off in massive numbers
The four major types of cultured whole pearls are akoya, South Sea, freshwater and
A. rice.
B. Thai.
C. blister.
D. Tahitian.
D. Tahitian
South Sea cultured pearls are produced principally in Australia, Indonesia, and
A. India.
B. Tahiti.
C. Japan.
D. the Philippines.
D. The Philippines
The oyster used to grow Tahitian cultured pearls is
A. Pinctada fucata.
B. Pinctada maxima.
C. Hyriopsis cumingi.
D. Pinctada margaritifera.
D. Pinctada margaritifera
The nacreous layer inside a pearl-bearing mollusk’s shell is called
A. mantle.
B. the gonad.
C. conchiolin.
D. mother-of-pearl.
A. Mantle
Which country produces the most freshwater cultured pearls?
A. Japan
B. China
C. Australia
D. United States
B. China
A number of similar cultured pearl strands bundled together is called a
A. hank.
B. mabe.
C. bushel.
D. pearl sac.
A. Hank
Seed pearls are
A. small imitation pearls.
B. very small natural pearls.
C. cultured pearls without a bead nucleus.
D. accidental byproducts of the pearl culturing process.
B. Very small natural pearls
In pearl culturing, the most difficult shape to produce is
A. oval.
B. drop.
C. round.
D. baroque.
C. Round
The largest gem-quality natural pearl known is the
A. Qajar.
B. Dudley.
C. Oriental.
D. La Peregrina.
B. Dudley
Pearl colors are
A. intense.
B. low in saturation.
C. high in saturation.
D. always light in tone.
B. Low in saturation
In the trade, Tahitian cultured pearls with a dark green-gray to blue-gray bodycolor and rose to purple overtones are called
A. peacock.
B. lavender.
C. pistachio.
D. aubergine.
A Peacock
Which overtone color increases the value of akoya cultured pearls with white bodycolor?
A. Rose
B. Green
C. Brown
D. Yellow
A. Rose
When mollusks live in cooler water, they form
A. larger pearls.
B. pearls with higher luster.
C. pearls with thicker nacre.
D. pearls with darker bodycolor
B. Pearls with higher luster
Pearls that show noticeable surface characteristics are
A. Lightly Spotted.
B. Heavily Spotted.
C. Severely Spotted.
D. Moderately Spotted.
D. Moderately Spotted
The best way to clean pearls is with
A. a steam cleaner.
B. an ultrasonic cleaner.
C. warm, mild soapy water.
D. commercial jewelry cleaners.
C. Warm, mild soapy water
The nacre quality classification described as “Nucleus not noticeable, no chalky appearance” is
A. Fair.
B. Excellent.
C. Very Good.
D. Acceptable.
D. Acceptable
The matching level that describes a group of pearls that have minor variations in uniformity is
A. Fair.
B. Good.
C. Excellent.
D. Very Good.
B. Good
Farmers of every cultured pearl type do at least which of these after harvest?
A. Wash, dry, and sort
B. Dry, bleach, and sort
C. Wash, bleach, and tint
D. Wash, dry, and irradiate
A. Wash, dry, and sort
Almost all Akoya and Chinese freshwater pearls are
A. dyed.
B. tinted.
C. bleached.
D. irradiated.
C. Bleached
Usually, the diameters of the cultured pearls in a hank vary from each other by no more than
A. 0.5 mm.
B. 1 mm.
C. 1.5 mm.
D. 2 mm.
A. 0.5 mm
Essence d’orient is a mixture of
A. plastic and calcite.
B. aragonite and varnish.
C. fish scales and varnish.
D. aragonite and conchiolin.
C. Fish scales and varnish
What happens when saltwater cultured pearls are exposed to gamma rays?
A. Nacre lightens
B. Nacre darkens
C. Bead nucleus darkens
D. Nacre and bead nucleus darken
C. Bead nucleus darkens
Where was jadeite first fashioned and used as an ornamental object?
A. China
B. Australia
C. East Africa
D. Central America
The finest-quality jadeite is called
A. Imperial.
B. Transvaal.
C. spinach green.
D. moss-in-snow.
A. Imperial
Jadeite’s finest green color is caused by
A. iron.
B. vanadium.
C. chromium.
D. color centers.
C. Chromium
The most valuable level of transparency in jadeite is
A. opaque.
B. translucent.
C. transparent.
D. semitransparent.
D. Semitransparent
The toughness of jadeite is
A. fair.
B. good.
C. excellent.
D. exceptional.
D. Exceptional
The finest texture category of jadeite is known as
A. top mine.
B. old mine.
C. new mine.
D. relatively old mine.
B. Old mine
Type B jadeite is
A. dyed jadeite.
B. untreated jadeite.
C. irradiated jadeite.
D. bleached and impregnated jadeite.
D. Bleached and impregnated jadeite
Type C jadeite is
A. dyed jadeite.
B. synthetic jadeite.
C. untreated jadeite.
D. irradiated jadeite.
A. Dyed jadeite
In Myanmar, the center of the jadeite-mining district is
A. Mogok.
B. Hpakan.
C. Rangoon.
D. Mong-Hsu.
B. Hpakan
Spots of color near the surface of a jadeite boulder, where the skin is thin enough to see through, are called
A. slices.
B. cracks.
C. windows.
D. show points.
D. Show points
Guatemala recently emerged as a valuable source of which of the following jadeite colors?
A. Black
B. Orange
C. Lavender
D. Moss-in-snow
A. Black
Polar jade is actually a very fine-quality
A. jadeite.
B. nephrite.
C. idocrase.
D. serpentine.
B. Nephrite
Heat treatment of jadeite might produce
A. black color.
B. orange color.
C. lavender color.
D. fine green color.
D. Fine green color
Spinach jade is used to describe a color of
A. jadeite.
B. nephrite.
C. serpentine.
D. Transvaal jade.
B. Nephrite
New Zealand is a major source of
A. jadeite.
B. nephrite.
C. idocrase.
D. hydrogrossular.
B. Nephrite
Opal is composed primarily of
A. silica.
B. carbon.
C. beryllium.
D. aluminum.
A. Silica
Most opal formed
A. 15 to 30 thousand years ago.
B. 150 to 300 thousand years ago.
C. 15 to 30 million years ago.
D. 150 to 300 million years ago.
C. 15 to 30 million years ago
Most opal contains
A. 3 to 10 percent water.
B. 15 to 20 percent water.
C. 25 to 30 percent water.
D. 30 to 35 percent water.
A. 3 to 10 percent water
What is semi-black opal’s background color?
A. Black
B. Brown
C. Grayish
D. Dark purple
C. Grayish
What is the transparency of gray-base black opal?
A. Opaque
B. Translucent
C. Transparent
D. Semitransparent
A. Opaque
What is the transparency range of white opal?
A. Translucent to opaque
B. Transparent to opaque
C. Semitransparent to translucent
D. Transparent to semitransparent
A. Translucent to Opaque
The type of matrix found as a layer in finished boulder opal is
A. basalt.
B. granite.
C. ironstone.
D. limestone.
C. Ironstone
Experts think fire opal’s background color is caused by
A. chromium.
B. iron impurities.
C. titanium oxides.
D. aluminum oxides
B. Iron Impurities
In opal, a pattern of large, distinct, usually rectangular patches of play-of-color with edges that touch each other is called
A. flash.
B. pinfire.
C. peacock.
D. harlequin.
D. Harleqeuin
Play-of-color that’s seen only when light travels through an opal to the eye is called
A. flash.
B. peacock.
C. harlequin.
D. contra luz.
D. Contra Luz
The first black opals were discovered in
A. Ouro Preto.
B. Massapequa.
C. Klein Spitzkoppe.
D. New South Wales.
D. New South Wales
What is the first step in evaluating an opal?
A. Evaluate the cut
B. Determine its type
C. Determine its clarity
D. Determine the ratio and type of play-of-color
B. Determine its type
Which treatment involves immersing opal in concentrated sulfuric acid?
A. Sugar
B. Smoke
C. Irradiation
D. Fracture filling
A. Sugar
Who created the first marketable synthetic opal?
A. John Slocum
B. Pierre Gilson
C. Carroll Chatham
D. Auguste Verneuil
B. Pierre Gilson
Plastic imitation opal was first marketed in the late 1980s in
A. Japan.
B. Europe.
C. Thailand.
D. Australia.
A. Japan
Cryptocrystalline quartz is known as
A. quartzite.
B. aventurine.
C. cairngorm.
D. chalcedony.
D. Chalcedony
Chalcedony with curved or angular bands or layers that differ in color and transparency is known as
A. sard.
B. onyx.
C. agate.
D. carnelian.
C. Agate
Which of the following has the smallest crystal size?
A. Twin crystals
B. Single crystals
C. Microcrystalline aggregates
D. Cryptocrystalline aggregates
D. Cryptocrystalline aggregates
In the nineteenth century, a major source of amethyst was discovered in
A. Brazil.
B. Russia.
C. Burma.
D. Zambia.
A. Brazil
The color of amethyst results from
A. chromium impurities.
B. magnesium impurities.
C. color centers acting on iron.
D. color centers acting on titanium.
C. Color centers acting on iron
One of amethyst’s finest colors is
A. light purple.
B. dark bronzy purple.
C. medium-dark bluish purple.
D. medium-dark strong reddish purple
D. Medium-dark strong reddish purple
The major commercial-quality amethyst source is
A. Brazil.
B. Uruguay.
C. Argentina.
D. Zimbabwe.
A. Brazil
“Maraba” amethyst is often
A. color zoned.
B. highly included.
C. highly saturated.
D. uniform in color.
D. Uniform in color
Dark amethyst is lightened by
A. heating.
B. diffusion.
C. irradiation.
D. heating followed by irradiation
A. Heating
Most of the citrine in the market is
A. naturally colored.
B. produced by heating amethyst.
C. produced by heating rock crystal.
D. produced by irradiating amethyst.
B. Produced by heating amethyst
The source of natural ametrine is
A. Brazil.
B. Bolivia.
C. Zambia.
D. Uruguay.
B. Bolivia
Tiger’s-eye quartz is a
A. twin crystal.
B. single crystal.
C. microcrystalline aggregate.
D. cryptocrystalline aggregate.
C. Microcrystalline aggregate
Which of the following gems has chatoyancy that’s caused by multiple slender crystals or channels?
A. Cat’s-eye quartz
B. Tiger’s-eye quartz
C. Hawk’s-eye quartz
D. Falcon’s-eye quartz
A. Cat's eye quartz
The color of chrysoprase is
A. blue.
B. yellow.
C. blue-green.
D. yellowish green
C. Blue-green
The trade term “black onyx” is used for
A. sard.
B. dark agate.
C. banded onyx.
D. treated black chalcedony.
D. Treated black chalcedony
Which of the following gems is the most economically important?
A. Iolite
B. Tanzanite
C. Andalusite
D. Chiastolite
B. Tanzanite
Where was tanzanite discovered?
A. Tunduru
B. Mangari
C. Merelani
D. Umba River Valley
C. Merelani
The name tanzanite was given to transparent blue zoisite by
A. Tiffany & Co.
B. Manuel D’Souza.
C. a Masai tribesman.
D. the Tanzanian government.
A. Tiffany & Co
Tanzanite’s best color is
A. dark purple or violet.
B. light purple or violet.
C. strongly saturated purple or violet.
D. strongly saturated blue or violetish blue.
D. Strongly saturated blue or violetish blue
Almost all tanzanite is
A. untreated.
B. irradiated.
C. heat-treated.
D. clarity enhanced.
C. Heat treated
Untreated tanzanite is typically
A. violet.
B. bluish.
C. purple.
D. brownish.
D. Brownish
Tanavyte is a trade name for
A. purple glass.
B. synthetic zoisite.
C. synthetic forsterite.
D. purple synthetic YAG.
D. Purple synthetic YAG
In iolite, the most valuable main face-up color is
A. blue.
B. gray.
C. violet.
D. yellow.
A. Blue
Top-color iolite is
A. untreated.
B. irradiated.
C. heat-treated.
D. diffusion-treated.
A. Untreated
Alexandrite was discovered in
A. 1830.
B. 1897.
C. 1955.
D. 1967.
A. 1830
The color change in alexandrite is caused by
A. iron.
B. cobalt.
C. chromium.
D. magnesium.
C. Chromium
What changes during alexandrite’s color-change effect?
A. Hue
B. Tone
C. Saturation
D. Tone and saturation
A. Hue
What color is top-quality alexandrite in daylight?
A. Red
B. Yellow
C. Bluish green
D. Yellowish green
C. Bluish green
The most-prized chatoyant gem in the world is
A. tiger’s-eye quartz.
B. hawk’s-eye quartz.
C. cat’s-eye tourmaline.
D. cat’s-eye chrysoberyl.
D. Cat's-eye chrysoberyl
Which of the following is a major source of cat’s-eye chrysoberyl?
A. Vietnam
B. Colombia
C. Sri Lanka
D. Cambodia
C. Sri Lanka
The color of imperial topaz is
A. green.
B. violetish blue.
C. brownish orange.
D. reddish orange to orange-red.
D. Reddish orange to orange-red
The most valuable topaz varieties are
A. pink and red.
B. green and blue.
C. pink and purple.
D. orange and yellow.
A. Pink and red
Most gem-quality topaz comes from
A. schists.
B. pegmatites.
C. metamorphic rocks.
D. hydrothermal veins.
B. Pegmatites
The term precious topaz is used for
A. red stones.
B. blue stones.
C. pink stones.
D. yellow-to-orange stones
D. yellow-to-orange stones
What is the most common color of untreated, natural topaz?
A. Pink
B. Colorless
C. Dark blue
D. Orange-red
B. Colorless
The major source of imperial topaz is
A. Mogok.
B. Nova Era.
C. Ouro Preto.
D. the Wah Wah mountain area.
C. Ouro Preto
In order to attain a treated pink color, yellow to reddish brown topaz must contain
A. iron.
B. cobalt.
C. chromium.
D. manganese.
C. Chromium
The finest aquamarine color is moderately strong,
A. light green-blue.
B. light greenish blue.
C. medium-dark bluish green to blue.
D. medium-dark blue to slightly greenish blue.
D. Medium-dark blue to slightly greenish blue
Which method is used to produce synthetic aquamarine?
A. Flux
B. Pulling
C. Flame fusion
D. Hydrothermal
D. Hydrothermal
The most important source of aquamarine is
A. Brazil.
B. Australia.
C. Mozambique.
D. United States.
A. Brazil
Which recent source is the leading producer of small, commercial-quality aquamarine?
A. China
B. Kenya
C. Colombia
D. United States
A. China
Most aquamarine has its color improved by
A. heat.
B. diffusion.
C. irradiation.
D. irradiation followed by heat.
A. Heat
What color is morganite beryl?
A. Pink
B. Green
C. Yellow
D. Dark blue
A. Pink
Which of the following is the rarest beryl?
A. Red beryl
B. Morganite
C. Aquamarine
D. Golden beryl
A. Red Beryl
The only source of red beryl is in
A. Utah.
B. Nevada.
C. Colorado.
D. California
A. Utah
Most gem tourmalines are
A. uvite.
B. schorl.
C. elbaite.
D. dravite.
C. Elbaite
Most gem tourmalines form in
A. marble.
B. limestone.
C. pegmatites.
D. metamorphic rock.
C. Pegmatites
The world’s largest producer of gem-quality tourmaline is
A. Brazil.
B. Zambia.
C. Tanzania.
D. Madagascar.
A. Brazil
The most expensive variety of tourmaline is
A. Paraiba.
B. chrome.
C. rubellite.
D. indicolite.
A. Paraiba
Paraiba tourmaline is colored by
A. iron.
B. cobalt.
C. copper.
D. chromium
C. Copper
Which of the following trade terms is used for blue tourmaline?
A. Chrome
B. Rubellite
C. Verdelite
D. Indicolite
D. Indicolite
Which of the following is the largest producer of chrome tourmaline?
A. Brazil
B. Tanzania
C. Sri Lanka
D. Madagascar
B. Tanzania
Rubellite tourmaline is colored by
A. iron.
B. copper.
C. chromium.
D. manganese.
D. Manganese
Many green and blue tourmalines are lightened by
A. heating.
B. bleaching.
C. irradiation.
D. irradiation followed by heating.
A. Heating
Many Paraiba tourmalines are
A. dyed.
B. heated.
C. irradiated.
D. fracture filled.
B. Heated
The cause of color in peridot is
A. iron.
B. nickel.
C. vanadium.
D. chromium.
A. Iron
Most of the world’s commercial-quality peridot is mined in
A. Russia.
B. Burma.
C. Arizona.
D. Pakistan
C. Arizona
The color of blue zircon is usually
A. natural.
B. due to irradiation.
C. due to heat treatment.
D. due to irradiation followed by heating.
C. Due to heat treatment
Metamict zircons are described as
A. low zircons.
B. high zircons.
C. normal zircons.
D. diffusion-treated zircons.
A. Low zircons


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