GIA Colored Stones Exam Questions And Answers With Verified Solutions 2025
Gems
Most _____ are minerals
United States and Mexico
Chrysocolla-in-chalcedony sources include the __________ & _____________
Uruguay
Fine-quality agate comes from Mexico, Brazil, and __________
Iris
_____ agate is a lovely phenomenal variety of agate. It's semitransparent to translucent and
shows iridescent colors when light is transmitted through thin slices.
Mineral
To be gem, a _____ must be beautiful, durable, and rare
Chinese red
______ ____ agate, commonly called southern red agate in the trade; usually has intense red,
white, or grayish color bands.
,precious and common
There are two broad opal categories: _________ and _________
Syntectonic and Redox
The 4 most representative Opal Formation models are the Weathering theory, the Microbe
theory, the ________ theory, and the _______ theory.
White
________ opal—Background color ranges from translucent white to medium gray; shows play-
of-color
Crystal
_________ opal—Background ranges from transparent to semitransparent; shows exceptional
play-of-color
common
Precious opal displays characteristic flashes of rainbow colors, called play-of-color, while
_______ opal—also known as potch opal—does not. _________ opal, which can occur in
attractive colors that make it highly desirable to consumers, is more widespread than precious
opal.
Water
________ opal (Jelly opal)—Background ranges from transparent to translucent; shows faint
play-of-color or no play-of-color at all
,Nucleus Visible
_________ ________ —The cultured pearl shows evidence of its bead nucleus through the
nacre
Good
________ Luster - Reflections are bright but not sharp and slightly hazy around the edges
(Pearls)
Neutrals, Near-Neutrals, & Hues
GIA groups Pearl bodycolors into three types:
Name
An appealing ________ can make a gem much easier to sell
Source Country
Changes that take place in gem's ____________________ can drastically affect its availability
and price
Treatments
____________ improve the marketability and availability of many gems.
, Emerald
In spite of treatment that is sometimes extensive, _________ is the number one colored stone
by value imported into the US.
Gem Treatments
Many consumers accept _____________________ if they're ethically disclosed and explained in
a positive way.
Amorphous
Lacking a regular crystal structure
Atom
The basic structure of all matter
Chemical Composition
Kinds and relative quantities of atoms that make up a material.
Chemical Element
A substance that consists of atoms of only one kind
Crystal Structure
Gems
Most _____ are minerals
United States and Mexico
Chrysocolla-in-chalcedony sources include the __________ & _____________
Uruguay
Fine-quality agate comes from Mexico, Brazil, and __________
Iris
_____ agate is a lovely phenomenal variety of agate. It's semitransparent to translucent and
shows iridescent colors when light is transmitted through thin slices.
Mineral
To be gem, a _____ must be beautiful, durable, and rare
Chinese red
______ ____ agate, commonly called southern red agate in the trade; usually has intense red,
white, or grayish color bands.
,precious and common
There are two broad opal categories: _________ and _________
Syntectonic and Redox
The 4 most representative Opal Formation models are the Weathering theory, the Microbe
theory, the ________ theory, and the _______ theory.
White
________ opal—Background color ranges from translucent white to medium gray; shows play-
of-color
Crystal
_________ opal—Background ranges from transparent to semitransparent; shows exceptional
play-of-color
common
Precious opal displays characteristic flashes of rainbow colors, called play-of-color, while
_______ opal—also known as potch opal—does not. _________ opal, which can occur in
attractive colors that make it highly desirable to consumers, is more widespread than precious
opal.
Water
________ opal (Jelly opal)—Background ranges from transparent to translucent; shows faint
play-of-color or no play-of-color at all
,Nucleus Visible
_________ ________ —The cultured pearl shows evidence of its bead nucleus through the
nacre
Good
________ Luster - Reflections are bright but not sharp and slightly hazy around the edges
(Pearls)
Neutrals, Near-Neutrals, & Hues
GIA groups Pearl bodycolors into three types:
Name
An appealing ________ can make a gem much easier to sell
Source Country
Changes that take place in gem's ____________________ can drastically affect its availability
and price
Treatments
____________ improve the marketability and availability of many gems.
, Emerald
In spite of treatment that is sometimes extensive, _________ is the number one colored stone
by value imported into the US.
Gem Treatments
Many consumers accept _____________________ if they're ethically disclosed and explained in
a positive way.
Amorphous
Lacking a regular crystal structure
Atom
The basic structure of all matter
Chemical Composition
Kinds and relative quantities of atoms that make up a material.
Chemical Element
A substance that consists of atoms of only one kind
Crystal Structure
