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GIA Colored Stones
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 | Placer |
A mass of tiny, randomly oriented crystals is called an _____ | Aggregate |
Rock formed by the crystallization of molten material is called _______ rock | Igneous |
A deposit where gems are eroded from their source rock, then transported away from the source are ______ | Alluvial |
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. “Paraíba” 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. mabé. 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 rosé 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. Rosé 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 Prêto. 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. Paraíba. B. chrome. C. rubellite. D. indicolite. | A. Paraiba |
Paraíba 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 Paraíba 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 |
Which countries produce the finest peridot? A. Myanmar and Pakistan B. Madagascar and Sri Lanka C. Afghanistan and Cambodia D. The United States and Brazil | A. Myanmar and Pakistan |
Spessartine is most commonly found in A. marble. B. limestone. C. pegmatite veins. D. metamorphic rock. | C. Pegmatite veins |
Which of the following has the widest color range? A. Rhodolite B. Almandine C. Spessartine D. Grossular | D. Grossular |
Tsavorite and hessonite are both varieties of A. pyrope. B. andradite. C. uvarovite. D. grossular. | D. Grossular |
All garnets have essentially the same A. inclusions. B. crystal structure. C. impurity elements. D. chemical composition. | B. Crystal structure |
Rhodolite is a mixture of A. pyrope and andradite. B. almandine and pyrope. C. spessartine and pyrope. D. spessartine and andradite | B. Almandine and pyrope |
The substitution of one chemical element for another in the crystal structure of a mineral is called A. charge transfer. B. metamorphism. C. isomorphous replacement. D. intervalence charge transfer. | C. Isomorphous replacement |
Mandarin garnet has been used as a trade name for A. pyrope. B. tsavorite. C. andradite. D. spessartine. | D. Spessartine |
Demantoid was first discovered in A. Brazil. B. Africa. C. Russia. D. Sri Lanka. | C. Russia |
Tsavorite is colored by A. iron. B. nickel. C. vanadium. D. chromium. | C. Vanadium |
The intense red color of spinel is caused by A. iron. B. chromium. C. manganese. D. color centers. | B. Chromium |
Horsetail inclusions are found in A. malaya. B. tsavorite. C. spessartine. D. demantoid | D. Demantoid |
The trade term malaya is used for a pinkish orange garnet that’s a mixture of A. pyrope and almandine. B. andradite and spessartine. C. pyrope, andradite, and almandine. D. pyrope, spessartine, and almandine | D. Pyrope, spessartine, almandine |
The most important source of rhodolite in recent years is A. Brazil. B. Burma. C. East Africa. D. United States. | C. East Africa |
The most valuable spinel color is A. red. B. green. C. violet. D. orange. | A. Red |
The most desirable, vibrant, and rare blue natural spinels are colored by A. iron. B. titanium. C. cobalt and iron. D. iron and titanium | C. Cobalt and iron |
The world’s major source of lapis lazuli is A. Chile. B. Russia. C. Afghanistan. D. United States. | C. Afghanistan |
The finest trade grade of lapis lazuli is A. Afghan. B. Chilean. C. Siberian. D. Egyptian. | A. Afghan |
The lapis lazuli trade grade that’s often spotted with green and shows obvious calcite is A. Afghan. B. Chilean. C. Siberian. D. Egyptian. | B. Chilean |
The finest color of turquoise is A. light blue. B. dark green-blue. C. dark greenish blue. D. intense medium blue. | D. Intense medium blue |
The purest blue colors of turquoise are caused by A. iron. B. cobalt. C. copper. D. titanium | C. Copper |
The trade term for top-color turquoise is A. Persian. B. Mexican. C. Egyptian. D. American. | A. Persian |
Which of the following does turquoise usually form in? A. Quartz B. Marble C. Granite D. Limonite | D. Limonite |
What is the color of the markings that sandstone matrix creates in turquoise? A. Tan B. Green C. Dark red D. Dark brown | D. Dark brown |
Stabilized turquoise is a trade term for A. synthetic turquoise. B. a turquoise imitation. C. reconstructed turquoise. D. polymer-impregnated turquoise. | D. Polymer-impregnated turquoise |
A new turquoise treatment that appeared in the 1980s and has been used to treat more than 10 million carats is A. diffusion. B. irradiation. C. heating and dyeing. D. the Zachery method. | D. The Zachery method |
The major source of turquoise today is A. Iran. B. Egypt. C. Afghanistan. D. southwestern US. | D. Southwestern US |
The major source for top-color turquoise today is A. Iran. B. China. C. Egypt. D. Afghanistan. | B. China |
Reconstructed turquoise is A. treated turquoise. B. imitation turquoise. C. synthetic turquoise. D. stabilized turquoise. | B. Imitation turquoise |
Malachite’s color is caused by A. nickel. B. copper. C. vanadium. D. chromium. | B. Copper |
The only commercial source of charoite is A. Iran. B. Russia. C. South Africa. D. United States. | B. Russia |
How many cleavage directions are found in feldspar, spodumene, and diopside? A. One B. Two C. Three D. Four | B. Two |
Which of the following three basic chemical elements do all feldspars contain? A. Aluminum, oxygen, and iron B. Potassium, calcium, and iron C. Aluminum, oxygen, and silicon D. Potassium, calcium, and sodium | C. Aluminum, oxygen, and silicon |
Moonstone is a variety of A. orthoclase. B. amazonite. C. microcline. D. spodumene. | A. Orthoclase |
In which era did moonstone go out of style? A. Art Deco B. Art Nouveau C. New Age movement D. Just after World War II | A. Art Deco |
The adularescence of the finest moonstones is A. blue. B. green. C. purple. D. yellow. | A. Blue |
Tiny tension cracks in moonstone are called A. lily pads. B. horsetails. C. centipedes. D. discoid fractures. | C. Centipedes |
Rainbow moonstone is a trade term for a type of A. orthoclase. B. amazonite. C. microcline. D. labradorite. | D. Labradorite |
Spectrolite is a variety of A. orthoclase. B. microcline. C. moonstone. D. labradorite. | D. Labradorite |
The greenish blue feldspar that has gridlike white streaks and resembles turquoise is A. amazonite. B. orthoclase. C. spectrolite. D. labradorite. | A. Amazonite |
What color is hiddenite? A. Yellow B. Light pink C. Orangy pink D. Medium green | D. Medium green |
Kunzite’s most common color is A. light pink. B. intense pink. C. intense violet. D. intense purple. | A. Light Pink |
Light-colored or colorless spodumene can be treated to a kunzite color by A. heating. B. diffusion. C. surface coatings. D. irradiation followed by careful heating. | D. Irradiaton followed by careful heating |
An intense, unstable green color can be created in spodumene by A. heating. B. diffusion. C. irradiation. D. irradiation followed by heating. | C. Irradiation |
The color of chrome diopside is A. natural. B. due to irradiation. C. due to heat treatment. D. due to diffusion treatment. | A. Natural |
Which of the following is a commercial source of chrome diopside? A. Brazil B. Russia C. Tanzania D. Sri Lanka | B. Russia |
Amber is actually A. lignite coal. B. fossilized mollusks. C. hardened tree resin. D. the remains of marine animals. | C. Hardened tree resin |
Immature amber is known as A. copal. B. ambroid. C. corozo nut. D. doum palm. | A. Copal |
The amber color that’s most valuable is A. red. B. brown. C. yellow. D. golden. | A. Red |
Which of the following is a calcium carbonate? A. Jet B. Amber C. Pink coral D. Golden coral | C. Pink Coral |
Coral’s most valuable color is A. red. B. pink. C. white. D. lavender. | A. Red |
Which of the following is a variety of conchiolin coral? A. Red B. Blue C. Black D. White | C. Black |
Which treatment can create a golden color from black coral? A. Coating B. Heating C. Bleaching D. Irradiation | C. Bleaching |
Which of the following organics shows a structure called “engine turning,” which looks like lines created on a lathe? A. Shell B. Coral C. Ivory D. Corozo nuts | C. Ivory |
Which animal’s tusk produces the most valuable ivory? A. Boar B. Walrus C. Narwhal D. Elephant | D. Elephant |
Paua is a Maori name for A. helmet shell. B. abalone shell. C. calcareous coral. D. conchiolin coral. | B. Abalone Shell |
Tortoise shell is composed of A. resin. B. protein. C. calcium. D. aragonite. | B. Protein |
Jet is an ornamental form of A. resin. B. calcium. C. conchiolin. D. lignite coal. | D. Lignite coal |
.The major source of jet is A. England. B. Australia. C. South Africa. D. United States. | A. England |
Which of the following gems is a natural glass? A. Sphene B. Kyanite C. Fluorite D. Moldavite | D. Moldavite |
The only source of gem-quality benitoite is A. Mogok. B. Ratnapura. C. California. D. Umba River Valley. | C. California |