GIA COLORED STONES FINAL EXAM 2 2026
FULL SOLVED QUESTIONS ANSWERS
GEMSTONE GRADING AND QUALITY REVIEW
SHEET
◉ Rocks altered by heat and pressure beneath Earth's surface are.
Answer: metamorphic
◉ Which type of deposit is usually the most profitable for colored
stone mining?.
Answer: secondary
◉ Which gem can crystallize in volcanic rock from gasses released
by magma?.
Answer: red beryl
◉ Emeralds are rarely found in placer deposits because they're.
Answer: unable to withstand much abrasion
◉ Which is a workable alluvial deposit of gem minerals with
economic potential?.
Answer: placers
,◉ Which is a deposit where gems eroded from the source rock and
remained in place nearby?.
Answer: eluvial
◉ from granite, pegmatite gems get exotic elements like.
Answer: beryllium, boron, and lithium
◉ Myanmar's famous Mogok ruby deposits were formed by.
Answer: metamorphic process
◉ most of the gems in tanzania's umba river valley are formed in.
Answer: placer deposits
◉ A deposit where gems are found in the rock that where they
formed is called.
Answer: primary deposit
◉ Which is a key locality for hydrothermal gems?.
Answer: Ouro Preto, Brazil
◉ Heat and pressure transform limestone into.
,Answer: marble
◉ which gem form by metamophosis.
Answer: tanzanite
◉ Most gemstones form in the.
Answer: continental crust
◉ kunzite is most often associated with.
Answer: tourmaline and beryl in pegmatites
◉ how heavy an object is in relation to its size.
Answer: density
◉ A two-phase inclusion is a cavity in a gem that's typically filled
with a.
Answer: liquid and a gas
◉ which type of twinning is caused by environmental change after a
gem forms.
Answer: polysynthetic
, ◉ which element caused red in ruby and green in emerald.
Answer: chromium
◉ A unit cell defines a mineral's.
Answer: basic identity
◉ which type of twinning looks as if two crystal halves are mirror
images.
Answer: contact twinning
◉ crystals that grow in a flux that is highly saturated with the
necessary elements tend to be -.
Answer: small
◉ which is classified in the orthorhombic crystal system.
Answer: topaz
◉ Which gems are cryptocrystalline aggregates?.
Answer: Chalcedony and turquoise
◉ Atoms in a gem that aren't part of its essential chemical
composition are called.
FULL SOLVED QUESTIONS ANSWERS
GEMSTONE GRADING AND QUALITY REVIEW
SHEET
◉ Rocks altered by heat and pressure beneath Earth's surface are.
Answer: metamorphic
◉ Which type of deposit is usually the most profitable for colored
stone mining?.
Answer: secondary
◉ Which gem can crystallize in volcanic rock from gasses released
by magma?.
Answer: red beryl
◉ Emeralds are rarely found in placer deposits because they're.
Answer: unable to withstand much abrasion
◉ Which is a workable alluvial deposit of gem minerals with
economic potential?.
Answer: placers
,◉ Which is a deposit where gems eroded from the source rock and
remained in place nearby?.
Answer: eluvial
◉ from granite, pegmatite gems get exotic elements like.
Answer: beryllium, boron, and lithium
◉ Myanmar's famous Mogok ruby deposits were formed by.
Answer: metamorphic process
◉ most of the gems in tanzania's umba river valley are formed in.
Answer: placer deposits
◉ A deposit where gems are found in the rock that where they
formed is called.
Answer: primary deposit
◉ Which is a key locality for hydrothermal gems?.
Answer: Ouro Preto, Brazil
◉ Heat and pressure transform limestone into.
,Answer: marble
◉ which gem form by metamophosis.
Answer: tanzanite
◉ Most gemstones form in the.
Answer: continental crust
◉ kunzite is most often associated with.
Answer: tourmaline and beryl in pegmatites
◉ how heavy an object is in relation to its size.
Answer: density
◉ A two-phase inclusion is a cavity in a gem that's typically filled
with a.
Answer: liquid and a gas
◉ which type of twinning is caused by environmental change after a
gem forms.
Answer: polysynthetic
, ◉ which element caused red in ruby and green in emerald.
Answer: chromium
◉ A unit cell defines a mineral's.
Answer: basic identity
◉ which type of twinning looks as if two crystal halves are mirror
images.
Answer: contact twinning
◉ crystals that grow in a flux that is highly saturated with the
necessary elements tend to be -.
Answer: small
◉ which is classified in the orthorhombic crystal system.
Answer: topaz
◉ Which gems are cryptocrystalline aggregates?.
Answer: Chalcedony and turquoise
◉ Atoms in a gem that aren't part of its essential chemical
composition are called.
