8/4/25, 11:42 PM Diamond & Diamond Grading Exam
Diamond & Diamond Grading ACTAUL EXAM 2025-2026 \LATEST
VERSION WITH COMPLETE QUESTIONS AND ACCURATE DETAILED
ANSWERS \VERIFIED 100% ALREADY GRADED A+
Habit Characteristic crystal shape of a specific mineral. (Assignment 7)
The length of time required for half of a group of atoms
Half-life
of a particular type (radioactive) to decay into another
type (non-radioactive). (Assignment 19)
Diamond synthesis method that mimics the pressure and
High pressure, high
temperature (HPHT) temperature conditions that lead to natural diamond
formation. (Assignment 19)
Igneous A category of rocks formed from a molten state. (Assignment 4)
Diamonds that can be repolished to improve their
Improvables
clarity to a VVS1 or VVS2 grade. (Assignment 17)
Clarity characteristic totally enclosed in a polished
Inclusion
gemstone or extending into it from the surface.
(Assignment 10)
A portion of the rough's original surface, or skin, that dips below
Indented Natural (IndN) the polished
diamond's surface, or an opening left when a surface-
reaching crystal drops out or is forced out during
polishing. (Assignment 10)
Minerals formed together with diamonds at great depths
Indicator minerals
and brought to the surface by the same kimberlites or
lamproites. (Assignment 5)
Diamond rough suitable for use in tools, drills,
Industrial rough
abrasives, and other industrial applications.
(Assignment 5)
Lines, angles, or curves that might appear whitish,
Internal Graining (IntGr)
colored, or reflective or affect transparency at 10X;
caused by irregularities in crystal growth. (Assignment
10)
A clarity treatment that uses a laser to expand an
Internal laser drilling (ILD)
existing cleavage or create a new one, allowing the
1/37
,8/4/25, 11:42 PM Diamond & Diamond Grading Exam
introduction of a bleaching solution. (Assignment 19)
Laser drilling within a diamond that doesn't reach the
Internal Laser Drilling (ILD)
surface; not plotted. (Assignment 10)
Exposure of a material to radiation; causes color change
Irradiation
in diamonds. (Assignment 19)
Dutch term for a diamond that has been cleaved, split,
Kaps
or sawn, but not fashioned. (Assignment 9)
Kerf A notch scratched into diamond rough to prepare it for cleaving.
(Assignment 9)
Diamond industry program designed to ensure that
Kimberley Process (KP)
diamonds crossing international borders are legitimate
and do not fund civil conflict or terrorism.
(Assignment 3)
Kimberlite An igneous rock that transports diamonds to the surface.
(Assignment 4)
An included diamond crystal that extends to the surface
Knot (K)
after fashioning. (Assignment 10)
An igneous rock, rarer than kimberlite, that transports
Lamproite
diamonds to the surface. (Assignment 4)
Laser Drill-hole (LDH) A tiny, surface-reaching tunnel produced by a laser light beam.
(Assignment 10)
Using a concentrated beam of laser light to reach a
Laser drilling
diamond's dark inclusions and disguise or eliminate
them. (Assignment 19)
Internal fractures (inclusions) or surface grooves
Laser Manufacturing
Remnants (LMR) (blemishes) created as a result of laser marking or
manufacturing. (Assignment 10)
A numerical expression of the relationship between the
Length-to-width ratio
length and width of a fancy cut, where the value for
width is one. (Assignment 16)
A machine used to accelerate electrons to high energy
Linear accelerator
along a straight path. (Assignment 19)
Lizard Skin Wavy or bumpy area on the surface of a polished diamond.
(Assignment 10)
A group of diamond merchants that united in 1890 to
London Diamond Syndicate
buy and sell rough diamonds. (Assignment 2)
2/37
,8/4/25, 11:42 PM Diamond & Diamond Grading Exam
A discounted price for buying an entire parcel, or a
Lot price
substantial part of it. (Assignment 20)
The length of the lower girdle facets expressed as a
Lower girdle facet percentage
percentage of the total distance between the girdle and
the culet. (Assignment 15)
Luster The appearance of a material's surface in reflected light.
(Assignment 8)
Macle A flat, triangular twinned diamond crystal. (Assignment 7)
Mantle Layer between the earth's crust and its core. (Assignment 4)
Secondary diamond deposit carried by rivers or
Marine deposit
streams to the ocean floor or shoreline. (Assignment
5)
The optical illusion that causes the ungraded diamond
Master-eye effect
to appear either lighter or darker than the masterstone,
depending on which side it's on. (Assignment 13)
A set of color-comparison diamonds that defines GIA
Masterstones
diamond color grades in the normal (D-to-Z) range.
(Assignment 13)
A grooved, white, non-reflective tray used for matching
Matching tray
sets of stones. (Assignment 20)
Buying agreement where a dealer entrusts merchandise
Memo
to a customer for inspection and approval without
requiring immediate payment. (Assignment 20)
Microdiamond testing Screening for the presence of tiny diamonds in a sample.
(Assignment 5)
Mixed cut A cutting style that combines step-cut and brilliant-cut facets.
(Assignment 16)
3/37
, 8/4/25, 11:42 PM Diamond & Diamond Grading Exam
A series of minute nicks along the facet junctions of a
Abrasion (Abr)
fashioned diamond; gives the edges a white or fuzzy
appearance. (Assignment 10)
Adamantine luster The highest degree of luster possible in a transparent material.
(Assignment 8)
A solid mass of individual, randomly oriented crystals,
Aggregate
intergrown or held together by a natural binding
agent. (Assignment 7)
A deposit where gems are eroded from their source
Alluvial deposit
rock, then transported away from the source and
further concentrated. (Assignment 5)
The angle at which a ray of light strikes a surface,
Angle of incidence
measured from the normal. (Assignment 8)
Angle of reflection The angle between the normal and a reflected ray of light.
(Assignment 8)
Annealing Using heat to stabilize irradiated color in gemstones. (Assignment
12)
An estimation of the value of an article, usually for
Appraisal
insurance purposes. (Assignment 1)
The result achieved by adding the smallest and largest
Average girdle diameter
girdle measurements of a round brilliant and dividing
by two. (Assignment 14)
Bast Frosted rough diamond. "Bark" in Dutch. (Assignment 9)
Very small feathers that extend from the girdle surface
Bearded Girdle (BG)
into the stone; can result from the cutting process.
(Assignment 10)
The slightly curving center of the long side of a pear,
Belly
marquise, heart, or oval. (Assignment 16)
A commitment to reserve a portion of the resources
Beneficiation
derived from any country for the economic
development of that country. (Assignment 3)
4/37
Diamond & Diamond Grading ACTAUL EXAM 2025-2026 \LATEST
VERSION WITH COMPLETE QUESTIONS AND ACCURATE DETAILED
ANSWERS \VERIFIED 100% ALREADY GRADED A+
Habit Characteristic crystal shape of a specific mineral. (Assignment 7)
The length of time required for half of a group of atoms
Half-life
of a particular type (radioactive) to decay into another
type (non-radioactive). (Assignment 19)
Diamond synthesis method that mimics the pressure and
High pressure, high
temperature (HPHT) temperature conditions that lead to natural diamond
formation. (Assignment 19)
Igneous A category of rocks formed from a molten state. (Assignment 4)
Diamonds that can be repolished to improve their
Improvables
clarity to a VVS1 or VVS2 grade. (Assignment 17)
Clarity characteristic totally enclosed in a polished
Inclusion
gemstone or extending into it from the surface.
(Assignment 10)
A portion of the rough's original surface, or skin, that dips below
Indented Natural (IndN) the polished
diamond's surface, or an opening left when a surface-
reaching crystal drops out or is forced out during
polishing. (Assignment 10)
Minerals formed together with diamonds at great depths
Indicator minerals
and brought to the surface by the same kimberlites or
lamproites. (Assignment 5)
Diamond rough suitable for use in tools, drills,
Industrial rough
abrasives, and other industrial applications.
(Assignment 5)
Lines, angles, or curves that might appear whitish,
Internal Graining (IntGr)
colored, or reflective or affect transparency at 10X;
caused by irregularities in crystal growth. (Assignment
10)
A clarity treatment that uses a laser to expand an
Internal laser drilling (ILD)
existing cleavage or create a new one, allowing the
1/37
,8/4/25, 11:42 PM Diamond & Diamond Grading Exam
introduction of a bleaching solution. (Assignment 19)
Laser drilling within a diamond that doesn't reach the
Internal Laser Drilling (ILD)
surface; not plotted. (Assignment 10)
Exposure of a material to radiation; causes color change
Irradiation
in diamonds. (Assignment 19)
Dutch term for a diamond that has been cleaved, split,
Kaps
or sawn, but not fashioned. (Assignment 9)
Kerf A notch scratched into diamond rough to prepare it for cleaving.
(Assignment 9)
Diamond industry program designed to ensure that
Kimberley Process (KP)
diamonds crossing international borders are legitimate
and do not fund civil conflict or terrorism.
(Assignment 3)
Kimberlite An igneous rock that transports diamonds to the surface.
(Assignment 4)
An included diamond crystal that extends to the surface
Knot (K)
after fashioning. (Assignment 10)
An igneous rock, rarer than kimberlite, that transports
Lamproite
diamonds to the surface. (Assignment 4)
Laser Drill-hole (LDH) A tiny, surface-reaching tunnel produced by a laser light beam.
(Assignment 10)
Using a concentrated beam of laser light to reach a
Laser drilling
diamond's dark inclusions and disguise or eliminate
them. (Assignment 19)
Internal fractures (inclusions) or surface grooves
Laser Manufacturing
Remnants (LMR) (blemishes) created as a result of laser marking or
manufacturing. (Assignment 10)
A numerical expression of the relationship between the
Length-to-width ratio
length and width of a fancy cut, where the value for
width is one. (Assignment 16)
A machine used to accelerate electrons to high energy
Linear accelerator
along a straight path. (Assignment 19)
Lizard Skin Wavy or bumpy area on the surface of a polished diamond.
(Assignment 10)
A group of diamond merchants that united in 1890 to
London Diamond Syndicate
buy and sell rough diamonds. (Assignment 2)
2/37
,8/4/25, 11:42 PM Diamond & Diamond Grading Exam
A discounted price for buying an entire parcel, or a
Lot price
substantial part of it. (Assignment 20)
The length of the lower girdle facets expressed as a
Lower girdle facet percentage
percentage of the total distance between the girdle and
the culet. (Assignment 15)
Luster The appearance of a material's surface in reflected light.
(Assignment 8)
Macle A flat, triangular twinned diamond crystal. (Assignment 7)
Mantle Layer between the earth's crust and its core. (Assignment 4)
Secondary diamond deposit carried by rivers or
Marine deposit
streams to the ocean floor or shoreline. (Assignment
5)
The optical illusion that causes the ungraded diamond
Master-eye effect
to appear either lighter or darker than the masterstone,
depending on which side it's on. (Assignment 13)
A set of color-comparison diamonds that defines GIA
Masterstones
diamond color grades in the normal (D-to-Z) range.
(Assignment 13)
A grooved, white, non-reflective tray used for matching
Matching tray
sets of stones. (Assignment 20)
Buying agreement where a dealer entrusts merchandise
Memo
to a customer for inspection and approval without
requiring immediate payment. (Assignment 20)
Microdiamond testing Screening for the presence of tiny diamonds in a sample.
(Assignment 5)
Mixed cut A cutting style that combines step-cut and brilliant-cut facets.
(Assignment 16)
3/37
, 8/4/25, 11:42 PM Diamond & Diamond Grading Exam
A series of minute nicks along the facet junctions of a
Abrasion (Abr)
fashioned diamond; gives the edges a white or fuzzy
appearance. (Assignment 10)
Adamantine luster The highest degree of luster possible in a transparent material.
(Assignment 8)
A solid mass of individual, randomly oriented crystals,
Aggregate
intergrown or held together by a natural binding
agent. (Assignment 7)
A deposit where gems are eroded from their source
Alluvial deposit
rock, then transported away from the source and
further concentrated. (Assignment 5)
The angle at which a ray of light strikes a surface,
Angle of incidence
measured from the normal. (Assignment 8)
Angle of reflection The angle between the normal and a reflected ray of light.
(Assignment 8)
Annealing Using heat to stabilize irradiated color in gemstones. (Assignment
12)
An estimation of the value of an article, usually for
Appraisal
insurance purposes. (Assignment 1)
The result achieved by adding the smallest and largest
Average girdle diameter
girdle measurements of a round brilliant and dividing
by two. (Assignment 14)
Bast Frosted rough diamond. "Bark" in Dutch. (Assignment 9)
Very small feathers that extend from the girdle surface
Bearded Girdle (BG)
into the stone; can result from the cutting process.
(Assignment 10)
The slightly curving center of the long side of a pear,
Belly
marquise, heart, or oval. (Assignment 16)
A commitment to reserve a portion of the resources
Beneficiation
derived from any country for the economic
development of that country. (Assignment 3)
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