GIA COLORED STONE FINAL EXAM
2025 QUESTIONS AND ANSWERS
By what date had Kokichi Mikimoto begun culturing whole pearls - ANS 1908
Synthetic gem materials - ANS Are not minerals
which of the following is an organic gem - ANS amber
which of the following is amorphous - ANS amber
a natural material that's made up of a mass of one or more kinds of mineral crystals is -
ANS rock
what group does alamandine belong to - ANS garnet
A gem produced by, or derived from, a living organism is - ANS organic
which of the following is a gem variety - ANS demantoid
the world's largest gem-consuming market is - ANS the US
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, a substance that consists of atoms of only one kind is a - ANS chemical element
Media attention in the 1990s regarding its treatment reduced consumer confidence in -
ANS emerald
a natural, inorganic substance with a characteristic chemical composition and usual crystal
structure is a - ANS mineral
most gems are - ANS minerals
To be a gem, a mineral must be beautiful, durable, and - ANS rare
a broad gem category based on chemical composition and crystal structure is called a -
ANS gem species
Many colored stones are mined by - ANS independent miners using small-scale mining
methods.
Rocks altered by heat and pressure beneath Earth's surface are - ANS metamorphic
Which type of deposit is usually the most profitable for colored stone mining? -
ANS secondary
Which gem can crystallize in volcanic rock from gasses released by magma? - ANS red beryl
Emeralds are rarely found in placer deposits because they're - ANS unable to withstand
much abrasion
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Which is a workable alluvial deposit of gem minerals with economic potential? - ANS placers
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, Which is a deposit where gems eroded from the source rock and remained in place nearby? -
ANS eluvial
from granite, pegmatite gems get exotic elements like - ANS beryllium, boron, and lithium
Myanmar's famous Mogok ruby deposits were formed by - ANS metamorphic process
most of the gems in tanzania's umba river valley are formed in - ANS placer deposits
A deposit where gems are found in the rock that where they formed is called - ANS primary
deposit
Which is a key locality for hydrothermal gems? - ANS Ouro Preto, Brazil
Heat and pressure transform limestone into - ANS marble
which gem form by metamophosis - ANS tanzanite
Most gemstones form in the - ANS continental crust
kunzite is most often associated with - ANS tourmaline and beryl in pegmatites
how heavy an object is in relation to its size - ANS density
A two-phase inclusion is a cavity in a gem that's typically filled with a - ANS liquid and a gas
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, which type of twinning is caused by environmental change after a gem forms -
ANS polysynthetic
which element caused red in ruby and green in emerald - ANS chromium
A unit cell defines a mineral's - ANS basic identity
which type of twinning looks as if two crystal halves are mirror images - ANS contact
twinning
crystals that grow in a flux that is highly saturated with the necessary elements tend to be - -
ANS small
which is classified in the orthorhombic crystal system - ANS topaz
Which gems are cryptocrystalline aggregates? - ANS Chalcedony and turquoise
Atoms in a gem that aren't part of its essential chemical composition are called - ANS trace
elements
Many fashioned rubies have shallow proportions because they're cut from - ANS flattened
crystals
Rough spinel often occurs as - ANS twinned crystals
Needles of actinolite found in emerald are classified as - ANS inclusions
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which aggregates crystals are visible only under very high magnification -
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ANS cryptocrystalline
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2025 QUESTIONS AND ANSWERS
By what date had Kokichi Mikimoto begun culturing whole pearls - ANS 1908
Synthetic gem materials - ANS Are not minerals
which of the following is an organic gem - ANS amber
which of the following is amorphous - ANS amber
a natural material that's made up of a mass of one or more kinds of mineral crystals is -
ANS rock
what group does alamandine belong to - ANS garnet
A gem produced by, or derived from, a living organism is - ANS organic
which of the following is a gem variety - ANS demantoid
the world's largest gem-consuming market is - ANS the US
1
Page
@COPYRIGHT SIRJOEL 2025/2026
, a substance that consists of atoms of only one kind is a - ANS chemical element
Media attention in the 1990s regarding its treatment reduced consumer confidence in -
ANS emerald
a natural, inorganic substance with a characteristic chemical composition and usual crystal
structure is a - ANS mineral
most gems are - ANS minerals
To be a gem, a mineral must be beautiful, durable, and - ANS rare
a broad gem category based on chemical composition and crystal structure is called a -
ANS gem species
Many colored stones are mined by - ANS independent miners using small-scale mining
methods.
Rocks altered by heat and pressure beneath Earth's surface are - ANS metamorphic
Which type of deposit is usually the most profitable for colored stone mining? -
ANS secondary
Which gem can crystallize in volcanic rock from gasses released by magma? - ANS red beryl
Emeralds are rarely found in placer deposits because they're - ANS unable to withstand
much abrasion
2
Page
Which is a workable alluvial deposit of gem minerals with economic potential? - ANS placers
@COPYRIGHT SIRJOEL 2025/2026
, Which is a deposit where gems eroded from the source rock and remained in place nearby? -
ANS eluvial
from granite, pegmatite gems get exotic elements like - ANS beryllium, boron, and lithium
Myanmar's famous Mogok ruby deposits were formed by - ANS metamorphic process
most of the gems in tanzania's umba river valley are formed in - ANS placer deposits
A deposit where gems are found in the rock that where they formed is called - ANS primary
deposit
Which is a key locality for hydrothermal gems? - ANS Ouro Preto, Brazil
Heat and pressure transform limestone into - ANS marble
which gem form by metamophosis - ANS tanzanite
Most gemstones form in the - ANS continental crust
kunzite is most often associated with - ANS tourmaline and beryl in pegmatites
how heavy an object is in relation to its size - ANS density
A two-phase inclusion is a cavity in a gem that's typically filled with a - ANS liquid and a gas
3
Page
@COPYRIGHT SIRJOEL 2025/2026
, which type of twinning is caused by environmental change after a gem forms -
ANS polysynthetic
which element caused red in ruby and green in emerald - ANS chromium
A unit cell defines a mineral's - ANS basic identity
which type of twinning looks as if two crystal halves are mirror images - ANS contact
twinning
crystals that grow in a flux that is highly saturated with the necessary elements tend to be - -
ANS small
which is classified in the orthorhombic crystal system - ANS topaz
Which gems are cryptocrystalline aggregates? - ANS Chalcedony and turquoise
Atoms in a gem that aren't part of its essential chemical composition are called - ANS trace
elements
Many fashioned rubies have shallow proportions because they're cut from - ANS flattened
crystals
Rough spinel often occurs as - ANS twinned crystals
Needles of actinolite found in emerald are classified as - ANS inclusions
4
which aggregates crystals are visible only under very high magnification -
Page
ANS cryptocrystalline
@COPYRIGHT SIRJOEL 2025/2026
