GIA Colored Stones Exam Questions And Answers With Verified Solutions 2025
A natural, inorganic substance with a characteristic chemical composition and usually
characteristic structure. - ✔✔Mineral
A cutting style that combines brilliant-cut and step cut facets. - ✔✔Mixed cut
Tiny nicks and pits caused by wear and damage to a gem's facet edges or culet. - ✔✔Abrasions
A pattern of dark vertical lines or bands shown by certain gems when viewed through a
spectroscope. - ✔✔Absorption spectrum
The cloudy bluish white light in a moonstone, caused by scattering of light. - ✔✔Adularescence
Chalcedony with a curved or angular bands or layers that differ in color and transparency . -
✔✔Agate
A mass of tiny, randomly oriented crystals. - ✔✔Aggregate
Common name for the Pinctada fucata oyster and the natural or cultured pearls it produces. -
✔✔Akoya
A gem colored by trace elements in its crystal structure. - ✔✔Allochromatic
A deposit where gems are eroded from their source rock, then transported away from their
source and further concentrated. - ✔✔Alluvial deposit
Lacking a regular crystal structure. - ✔✔Amorphous
,A crystalized form of calcium carbonate found in nacre. - ✔✔Aragonite
Two or more separate pieces of material joined to form a unit. - ✔✔Assembled stone
Crossing of chatoyant bands, creating a star in the dome of cabochon. - ✔✔Asterism
The basic structural unit of all matter. - ✔✔Atom
A glittery effect caused by light reflecting from small, flat inclusions within a gemstone. -
✔✔Aventurescence
An opal's bodycolor, independent of its play-of-color. - ✔✔Background color
A bead used as the core of a cultured pearl, usually made from a freshwater mussel shell. -
✔✔Bead nucleus
A treatment that uses chemicals to lighten or remove color. - ✔✔Bleaching
Characteristic or irregularity confined to the surface of a polished gemstone. - ✔✔Blemish
Trade term for a highly prized, vivid blue adularescence displayed by the finest moonstone. -
✔✔Blue Sheen
A gemstone's basic color, determined by its selective absorption of light. - ✔✔Bodycolor
A crystal growth habit with a bumpy appearance similar to a bunch of grapes. - ✔✔Botryoidal
,Thin layers of precious opal, cut to include matrix. - ✔✔Boulder opal
A cylindrical synthetic crystal produced by the flame-fusion process. - ✔✔Boule
Light that eventually returns to the eye after entering a gem through the crown, reflecting off
its pavilion facets, and exiting back through the crown. - ✔✔Brilliance
Cutting style with triangular or kite-shaped facets that radiate from the center toward girdle. -
✔✔Brilliant cut
A smoothly rounded polished gem with a domed top and a flat or curved base. - ✔✔Cabochon
A non-nacreous natural "pearl". - ✔✔Calcareous concretion
Gemstone sizes cut to fit standard mountings. - ✔✔Calibrated sizes
A gem carving style in which the design often a women's profile, projects slightly from a flat or
curved surface. - ✔✔Cameo
An opening that extends into a gem from the surface. - ✔✔Cavity
Tiny tension cracks in a moonstone that interfere with adularescence and reduce value. -
✔✔Centipedes
A process in which ground powder is heated, sometimes under pressure, to produce a fine-
grained solid material. - ✔✔Ceramic process
, A document that indicates a stone's geographic origin, based on its inclusions and trace
element chemistry. - ✔✔Certificate of origin
A cryptocrystalline quartz aggregate. - ✔✔Chalcedony
A process where the electrons that selectively absorb light are passed back and forth between
neighboring impurity ions. - ✔✔Charge transfer
Bands of light in certain gems, caused by reflection of light from many parallel, needle-like
inclusions or hollow tubes. - ✔✔Chatoyancy
Kinds and relative quantities of atoms that make up a material. - ✔✔Chemical composition
A substance that consists of atoms of only one kind. - ✔✔Chemical element
A damaged area on a gem, usually near the girdle. - ✔✔Chip
Trade term for a vibrant green tourmaline that's colored by traces of vanadium, chromium, or
both. - ✔✔Chrome tourmaline
A pearl with one or more grooved or ridged rings all the way around it. - ✔✔Circled pearl
A smooth, flat break in a gemstone parallel to planes of atomic weakness, caused by weak or
fewer bonds between atoms or both. - ✔✔Cleavage
Any hazy or milky area that cannot be described as a feather, fingerprint, or group of included
crystals or needles. - ✔✔Cloud
A natural, inorganic substance with a characteristic chemical composition and usually
characteristic structure. - ✔✔Mineral
A cutting style that combines brilliant-cut and step cut facets. - ✔✔Mixed cut
Tiny nicks and pits caused by wear and damage to a gem's facet edges or culet. - ✔✔Abrasions
A pattern of dark vertical lines or bands shown by certain gems when viewed through a
spectroscope. - ✔✔Absorption spectrum
The cloudy bluish white light in a moonstone, caused by scattering of light. - ✔✔Adularescence
Chalcedony with a curved or angular bands or layers that differ in color and transparency . -
✔✔Agate
A mass of tiny, randomly oriented crystals. - ✔✔Aggregate
Common name for the Pinctada fucata oyster and the natural or cultured pearls it produces. -
✔✔Akoya
A gem colored by trace elements in its crystal structure. - ✔✔Allochromatic
A deposit where gems are eroded from their source rock, then transported away from their
source and further concentrated. - ✔✔Alluvial deposit
Lacking a regular crystal structure. - ✔✔Amorphous
,A crystalized form of calcium carbonate found in nacre. - ✔✔Aragonite
Two or more separate pieces of material joined to form a unit. - ✔✔Assembled stone
Crossing of chatoyant bands, creating a star in the dome of cabochon. - ✔✔Asterism
The basic structural unit of all matter. - ✔✔Atom
A glittery effect caused by light reflecting from small, flat inclusions within a gemstone. -
✔✔Aventurescence
An opal's bodycolor, independent of its play-of-color. - ✔✔Background color
A bead used as the core of a cultured pearl, usually made from a freshwater mussel shell. -
✔✔Bead nucleus
A treatment that uses chemicals to lighten or remove color. - ✔✔Bleaching
Characteristic or irregularity confined to the surface of a polished gemstone. - ✔✔Blemish
Trade term for a highly prized, vivid blue adularescence displayed by the finest moonstone. -
✔✔Blue Sheen
A gemstone's basic color, determined by its selective absorption of light. - ✔✔Bodycolor
A crystal growth habit with a bumpy appearance similar to a bunch of grapes. - ✔✔Botryoidal
,Thin layers of precious opal, cut to include matrix. - ✔✔Boulder opal
A cylindrical synthetic crystal produced by the flame-fusion process. - ✔✔Boule
Light that eventually returns to the eye after entering a gem through the crown, reflecting off
its pavilion facets, and exiting back through the crown. - ✔✔Brilliance
Cutting style with triangular or kite-shaped facets that radiate from the center toward girdle. -
✔✔Brilliant cut
A smoothly rounded polished gem with a domed top and a flat or curved base. - ✔✔Cabochon
A non-nacreous natural "pearl". - ✔✔Calcareous concretion
Gemstone sizes cut to fit standard mountings. - ✔✔Calibrated sizes
A gem carving style in which the design often a women's profile, projects slightly from a flat or
curved surface. - ✔✔Cameo
An opening that extends into a gem from the surface. - ✔✔Cavity
Tiny tension cracks in a moonstone that interfere with adularescence and reduce value. -
✔✔Centipedes
A process in which ground powder is heated, sometimes under pressure, to produce a fine-
grained solid material. - ✔✔Ceramic process
, A document that indicates a stone's geographic origin, based on its inclusions and trace
element chemistry. - ✔✔Certificate of origin
A cryptocrystalline quartz aggregate. - ✔✔Chalcedony
A process where the electrons that selectively absorb light are passed back and forth between
neighboring impurity ions. - ✔✔Charge transfer
Bands of light in certain gems, caused by reflection of light from many parallel, needle-like
inclusions or hollow tubes. - ✔✔Chatoyancy
Kinds and relative quantities of atoms that make up a material. - ✔✔Chemical composition
A substance that consists of atoms of only one kind. - ✔✔Chemical element
A damaged area on a gem, usually near the girdle. - ✔✔Chip
Trade term for a vibrant green tourmaline that's colored by traces of vanadium, chromium, or
both. - ✔✔Chrome tourmaline
A pearl with one or more grooved or ridged rings all the way around it. - ✔✔Circled pearl
A smooth, flat break in a gemstone parallel to planes of atomic weakness, caused by weak or
fewer bonds between atoms or both. - ✔✔Cleavage
Any hazy or milky area that cannot be described as a feather, fingerprint, or group of included
crystals or needles. - ✔✔Cloud
