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GIA Colored Stones Assignment 19:
Opal Questions and Correct Answers
silica spheres Answer: Precious opal is made of
billions of uniform submicroscopic _________
___________, stacked in an orderly pattern.
light Answer: Play-of-color is produced by the
interaction of _________ with opals internal structure
of stacked silica spheres.
black opal Answer: _________ _________
commands the highest prices of all opal types.
white opal Answer: _________ ________ makes of
the bulk of commercial-quality opal on the market.
matrix backing Answer: ____________
____________ often makes boulder opal more durable
than other types of opal.
red orange, red Answer: The most valuable fire opals
usually display uniform ________-___________ to
bright _______ color.
Pretest - Stuvia US
, 2
fire opal Answer: _______ _______ is one of the few
opal types that manufacturers cut as faceted
gemstones
thin Answer: Assembled opal makes it possible to
make attractive finished gems from _______ opal
pieces.
vary widely Answer: Individual opals can ________
_________ in appearance and quality
color, pattern, clarity Answer: ____________,
____________, and ___________ combine to create
an opal's unique beauty. (CPC)
background color Answer: Opals are often divided
into types based on ________________ _________.
spectrum Answer: The rarest play-of-color contains
hues that range across the entire _____________.
red Answer: _____ is often considered the most
desirable play-of-color.
Pretest - Stuvia US
GIA Colored Stones Assignment 19:
Opal Questions and Correct Answers
silica spheres Answer: Precious opal is made of
billions of uniform submicroscopic _________
___________, stacked in an orderly pattern.
light Answer: Play-of-color is produced by the
interaction of _________ with opals internal structure
of stacked silica spheres.
black opal Answer: _________ _________
commands the highest prices of all opal types.
white opal Answer: _________ ________ makes of
the bulk of commercial-quality opal on the market.
matrix backing Answer: ____________
____________ often makes boulder opal more durable
than other types of opal.
red orange, red Answer: The most valuable fire opals
usually display uniform ________-___________ to
bright _______ color.
Pretest - Stuvia US
, 2
fire opal Answer: _______ _______ is one of the few
opal types that manufacturers cut as faceted
gemstones
thin Answer: Assembled opal makes it possible to
make attractive finished gems from _______ opal
pieces.
vary widely Answer: Individual opals can ________
_________ in appearance and quality
color, pattern, clarity Answer: ____________,
____________, and ___________ combine to create
an opal's unique beauty. (CPC)
background color Answer: Opals are often divided
into types based on ________________ _________.
spectrum Answer: The rarest play-of-color contains
hues that range across the entire _____________.
red Answer: _____ is often considered the most
desirable play-of-color.
Pretest - Stuvia US
