GIA Diamonds and Diamond Grading Exam {1513 Questions
& Answers 2025 }TESTBANK
Aggregate - CORRECT ANSWER a solid mass of individual, randomly oriented
crystals, intergrown or held together by a natural binding agent
Cleavage plane - CORRECT ANSWER plane parallel to a possible crystal face,
where a diamond can split cleanly when struck
covalent bond - CORRECT ANSWER a chemical bond formed by two atoms sharing
electrons
crystal - CORRECT ANSWER solid matter with atoms arranged in a regular,
repeating pattern
crystalline - CORRECT ANSWER composed of crystals or related to crystals
crystal planes - CORRECT ANSWER internal directions parallel to a mineral's unit
cell surfaces
crystal shape (form) - CORRECT ANSWER geometric shape of a well-formed
crystal
crystal structure (lattice) - CORRECT ANSWER regular, repeating arrangement of
atoms in a mineral
crystal systems - CORRECT ANSWER categories of crystals based on their
symmetry and internal structure
doubling - CORRECT ANSWER the appearance of double images of a gemstone's
facet junctions on the side opposite the viewer
doubly refractive (anisotropic) - CORRECT ANSWER possessing different physical
or optical properties in different crystal directions
glassie - CORRECT ANSWER a well-shaped, transparent, octahedral diamond
crystal with sharp, square edges
,glide plane - CORRECT ANSWER crystal distortion caused during growth when
one part of the lattice is offset in relation to the rest
graining (grain lines) - CORRECT ANSWER visible, shadow-like lines in a diamond
caused by irregularities in the crystal structure
Beneficiation - CORRECT ANSWER A commitment to reserve a portion of the
resources derived from any country for the economic development of that
country.
Blemish - CORRECT ANSWER Clarity characteristic that's confined to the surface
of a polished gemstone. Characteristic or irregularity confined to the surface of a
polished gemstone.
Blockchain - CORRECT ANSWER A shared, unalterable ledger used to record
transactions and track assets through a supply chain or business network.
Blocking - CORRECT ANSWER Placing the first 17 or 18 facets on a diamond,
including the crown and pavilion main facets, table, and sometimes a culet.
Bort - CORRECT ANSWER A form of industrial-grade diamond that usually occurs
as very included single crystals in a range of yellows, grays, and browns.
Bow-tie - CORRECT ANSWER A dark area across the center of an elongated
brilliant cut.
Brightfield illumination - CORRECT ANSWER Lighting a diamondfrom below to
create a bright background.
Brightness - CORRECT ANSWER The effect of all the diamond's internal and
external reflections of white light.
Brilliant cut - CORRECT ANSWER Cutting style with triangular or kite-shaped
facets that radiate from the center toward the girdle.
Brillianteering - CORRECT ANSWER Placement and polishing of the star and upper
and lower girdle facets.
Bruting - CORRECT ANSWER Forming the basic face-up outline of a round or
rounded shape diamond to prepare it for faceting.
Bulk sampling - CORRECT ANSWER Large-scale character sampling.
,Carbonado - CORRECT ANSWER An aggregate of many randomly oriented
interlocking tiny diamond crystals that is the toughest form of diamond.
Carbonate - CORRECT ANSWER A class of chemical compounds that contain
carbon and oxygen.
Catalyst - CORRECT ANSWER A substance that increases the rate of a chemical
reaction.
Cave mining - CORRECT ANSWER An underground mining technique in which
orebody is drilled beneath the surface, loosened, and collected as it falls.
Central Selling Organisation (CSO) - CORRECT ANSWER An agency designed to
purchase, sort, evaluate, and sell rough diamonds.
Character sampling - CORRECT ANSWER Testing for the size, shape, clarity, and
color of the diamonds in a deposit.
Characteristic color - CORRECT ANSWER The basic face-up color of a colored
diamond.
Clarity characteristic - CORRECT ANSWER Internal or external feature of a
gemstone that helps determine its quality.
Cleavage - CORRECT ANSWER A smooth, flat break in a gemstone parallel to
planes of atomic weakness.
Cleavage plane - CORRECT ANSWER Plane parallel to a possible crystal face,
where a diamond can split cleanly when struck.
Cleaving - CORRECT ANSWER Dividing a diamond into two or more pieces along a
cleavage plane.
CLIPPIR diamonds - CORRECT ANSWER Cullinan-like, Large, Inclusion-Poor, Pure,
Irregular, and Resorbed diamond.
Color center - CORRECT ANSWER A small defect in the atomic structure of a
material that can absorb light and give rise to a color. Structural defect that
influences an object's absorption of light and can cause its color.
Color lamellae - CORRECT ANSWER Closely spaced grain lines where color
concentrates.
, Coning - CORRECT ANSWER The process of forming the pavilion angle by
gradually polishing off the extra material at different angles.
Consignment - CORRECT ANSWER A selection of goods loaned to a dealer by
another wholesaler or a gem cutter.
Core - CORRECT ANSWER Earth's innermost layer.
Cost-plus model - CORRECT ANSWER Model in which final sale price is based on
the cost to produce the product plus a small markup.
Covalent bond - CORRECT ANSWER A chemical bond formed by two atoms
sharing electrons.
Craftsmanship - CORRECT ANSWER The care that goes into the fashioning of a
polished diamond, as confirmed by its finish.
Cratons - CORRECT ANSWER Ancient, large, and stable parts of the earth's
continental crust.
Critical angle - CORRECT ANSWER Angle between the normal and the maximum
angle of refraction, which is the largest angle at which rays inside the diamond
can escape.
Crossed polarizers - CORRECT ANSWER Two polarizers with their light-
transmitting directions aligned perpendicularly so light cannot transmit through
them.
Crown angle - CORRECT ANSWER The angle formed by the bezel facets and the
girdle plane.
Crown height percentage - CORRECT ANSWER The distance from the girdle plane
to the table, expressed as a percentage of average girdle diameter.
Crust - CORRECT ANSWER The surface and outermost layer of the earth.
Crustal diamond - CORRECT ANSWER Rare diamond that forms in the continental
crust or near the earth's surface due to meteorite impact or tectonic plate
collision.
& Answers 2025 }TESTBANK
Aggregate - CORRECT ANSWER a solid mass of individual, randomly oriented
crystals, intergrown or held together by a natural binding agent
Cleavage plane - CORRECT ANSWER plane parallel to a possible crystal face,
where a diamond can split cleanly when struck
covalent bond - CORRECT ANSWER a chemical bond formed by two atoms sharing
electrons
crystal - CORRECT ANSWER solid matter with atoms arranged in a regular,
repeating pattern
crystalline - CORRECT ANSWER composed of crystals or related to crystals
crystal planes - CORRECT ANSWER internal directions parallel to a mineral's unit
cell surfaces
crystal shape (form) - CORRECT ANSWER geometric shape of a well-formed
crystal
crystal structure (lattice) - CORRECT ANSWER regular, repeating arrangement of
atoms in a mineral
crystal systems - CORRECT ANSWER categories of crystals based on their
symmetry and internal structure
doubling - CORRECT ANSWER the appearance of double images of a gemstone's
facet junctions on the side opposite the viewer
doubly refractive (anisotropic) - CORRECT ANSWER possessing different physical
or optical properties in different crystal directions
glassie - CORRECT ANSWER a well-shaped, transparent, octahedral diamond
crystal with sharp, square edges
,glide plane - CORRECT ANSWER crystal distortion caused during growth when
one part of the lattice is offset in relation to the rest
graining (grain lines) - CORRECT ANSWER visible, shadow-like lines in a diamond
caused by irregularities in the crystal structure
Beneficiation - CORRECT ANSWER A commitment to reserve a portion of the
resources derived from any country for the economic development of that
country.
Blemish - CORRECT ANSWER Clarity characteristic that's confined to the surface
of a polished gemstone. Characteristic or irregularity confined to the surface of a
polished gemstone.
Blockchain - CORRECT ANSWER A shared, unalterable ledger used to record
transactions and track assets through a supply chain or business network.
Blocking - CORRECT ANSWER Placing the first 17 or 18 facets on a diamond,
including the crown and pavilion main facets, table, and sometimes a culet.
Bort - CORRECT ANSWER A form of industrial-grade diamond that usually occurs
as very included single crystals in a range of yellows, grays, and browns.
Bow-tie - CORRECT ANSWER A dark area across the center of an elongated
brilliant cut.
Brightfield illumination - CORRECT ANSWER Lighting a diamondfrom below to
create a bright background.
Brightness - CORRECT ANSWER The effect of all the diamond's internal and
external reflections of white light.
Brilliant cut - CORRECT ANSWER Cutting style with triangular or kite-shaped
facets that radiate from the center toward the girdle.
Brillianteering - CORRECT ANSWER Placement and polishing of the star and upper
and lower girdle facets.
Bruting - CORRECT ANSWER Forming the basic face-up outline of a round or
rounded shape diamond to prepare it for faceting.
Bulk sampling - CORRECT ANSWER Large-scale character sampling.
,Carbonado - CORRECT ANSWER An aggregate of many randomly oriented
interlocking tiny diamond crystals that is the toughest form of diamond.
Carbonate - CORRECT ANSWER A class of chemical compounds that contain
carbon and oxygen.
Catalyst - CORRECT ANSWER A substance that increases the rate of a chemical
reaction.
Cave mining - CORRECT ANSWER An underground mining technique in which
orebody is drilled beneath the surface, loosened, and collected as it falls.
Central Selling Organisation (CSO) - CORRECT ANSWER An agency designed to
purchase, sort, evaluate, and sell rough diamonds.
Character sampling - CORRECT ANSWER Testing for the size, shape, clarity, and
color of the diamonds in a deposit.
Characteristic color - CORRECT ANSWER The basic face-up color of a colored
diamond.
Clarity characteristic - CORRECT ANSWER Internal or external feature of a
gemstone that helps determine its quality.
Cleavage - CORRECT ANSWER A smooth, flat break in a gemstone parallel to
planes of atomic weakness.
Cleavage plane - CORRECT ANSWER Plane parallel to a possible crystal face,
where a diamond can split cleanly when struck.
Cleaving - CORRECT ANSWER Dividing a diamond into two or more pieces along a
cleavage plane.
CLIPPIR diamonds - CORRECT ANSWER Cullinan-like, Large, Inclusion-Poor, Pure,
Irregular, and Resorbed diamond.
Color center - CORRECT ANSWER A small defect in the atomic structure of a
material that can absorb light and give rise to a color. Structural defect that
influences an object's absorption of light and can cause its color.
Color lamellae - CORRECT ANSWER Closely spaced grain lines where color
concentrates.
, Coning - CORRECT ANSWER The process of forming the pavilion angle by
gradually polishing off the extra material at different angles.
Consignment - CORRECT ANSWER A selection of goods loaned to a dealer by
another wholesaler or a gem cutter.
Core - CORRECT ANSWER Earth's innermost layer.
Cost-plus model - CORRECT ANSWER Model in which final sale price is based on
the cost to produce the product plus a small markup.
Covalent bond - CORRECT ANSWER A chemical bond formed by two atoms
sharing electrons.
Craftsmanship - CORRECT ANSWER The care that goes into the fashioning of a
polished diamond, as confirmed by its finish.
Cratons - CORRECT ANSWER Ancient, large, and stable parts of the earth's
continental crust.
Critical angle - CORRECT ANSWER Angle between the normal and the maximum
angle of refraction, which is the largest angle at which rays inside the diamond
can escape.
Crossed polarizers - CORRECT ANSWER Two polarizers with their light-
transmitting directions aligned perpendicularly so light cannot transmit through
them.
Crown angle - CORRECT ANSWER The angle formed by the bezel facets and the
girdle plane.
Crown height percentage - CORRECT ANSWER The distance from the girdle plane
to the table, expressed as a percentage of average girdle diameter.
Crust - CORRECT ANSWER The surface and outermost layer of the earth.
Crustal diamond - CORRECT ANSWER Rare diamond that forms in the continental
crust or near the earth's surface due to meteorite impact or tectonic plate
collision.
