DIAMOND & DIAMOND GRADING
EXAM QUESTIONS AND ANSWERS
GRADED A+ 2025/2026
Abrasion (Abr) - ANS A series of minute nicks along the facet junctions of a fashioned
diamond; gives the edges a white or fuzzy appearance. (Assignment 10)
Adamantine luster - ANS The highest degree of luster possible in a transparent material.
(Assignment 8)
Aggregate - ANS A solid mass of individual, randomly oriented crystals, intergrown or held
together by a natural binding agent. (Assignment 7)
Alluvial deposit - ANS A deposit where gems are eroded from their source rock, then
transported away from the source and further concentrated. (Assignment 5)
Angle of incidence - ANS The angle at which a ray of light strikes a surface, measured from
the normal. (Assignment 8)
Angle of reflection - ANS The angle between the normal and a reflected ray of light.
(Assignment 8)
Annealing - ANS Using heat to stabilize irradiated color in gemstones. (Assignment 12)
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Appraisal - ANS An estimation of the value of an article, usually for insurance purposes.
(Assignment 1)
Average girdle diameter - ANS The result achieved by adding the smallest and largest girdle
measurements of a round brilliant and dividing by two. (Assignment 14)
Bast - ANS Frosted rough diamond. "Bark" in Dutch. (Assignment 9)
Bearded Girdle (BG) - ANS Very small feathers that extend from the girdle surface into the
stone; can result from the cutting process. (Assignment 10)
Belly - ANS The slightly curving center of the long side of a pear, marquise, heart, or oval.
(Assignment 16)
Beneficiation - ANS A commitment to reserve a portion of the resources derived from any
country for the economic development of that country. (Assignment 3)
Best Practices Principles (BPP) - ANS De Beers' formalized commitment of itself and its
sightholders to the highest ethical standards. (Assignment 3)
Blemish - ANS Clarity characteristic that's confined to the surface of a polished gemstone.
(Assignment 10)
Block caving - ANS Underground mining that involves building a concrete-lined tunnel under
an ore deposit, then collecting the ore through openings in the liner. (Assignment 6)
Blocking - ANS Placing the first 17 or 18 facets on a diamond. (Assignment 9)
Bow-tie - ANS A dark area across the center of an elongated brilliant cut. (Assignment 16)
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Brick-and-mortar retailer - ANS A traditional store consisting of walls and a fixed location.
(Assignment 3)
Brightness - ANS The effect of all the diamond's internal and external reflections of white
light. (Assignment 8)
Brilliant cut - ANS A cutting style in which triangular and kite-shaped facets radiate from a
gem's center toward its girdle. (Assignment 16)
Brillianteering - ANS Placement and polishing of the star and upper and lower girdle facets.
(Assignment 9)
Bruise (Br) - ANS A tiny area of impact accompanied by very small, root-like feathers visible at
10X magnification; typically occurs at a facet junction. (Assignment 10)
Bruting - ANS Forming the basic face-up outline of a diamond to prepare it for faceting.
(Assignment 9)
Bulk sampling - ANS Large-scale character sampling. (Assignment 5)
Burn Marks (Brn) - ANS Hazy surface areas that result from excessive heat or from uneven
polishing caused by structural irregularities; also called polish marks or burned facets.
(Assignment 10)
Cavity (Cv) - ANS An angular opening created when part of a feather breaks away.
(Assignment 10)
Central Selling Organisation (CSO) - ANS An agency designed to purchase, sort, evaluate, and
sell rough diamonds. (Assignment 2)
Character sampling - ANS Testing for the size, shape, clarity, and color of the diamonds in a
deposit. (Assignment 5)
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Characteristic color - ANS The basic color of a fancy-colored diamond. (Assignment 13)
Chemical vapor deposition (CVD) - ANS An industrial process adapted to allow growth of
synthetic diamond from carbon-rich gas in thin layers onto a silicon or diamond surface.
(Assignment 19)
Chip (Ch) - ANS A shallow opening caused by damage to the stone's surface; typically occurs
at a girdle edge, facet junction, or culet. (Assignment 10)
Clarity characteristic - ANS Internal or external feature of a gemstone that helps determine its
quality and establish its identity. (Assignment 10)
Cleavage (Cl) - ANS Large, severe, straight break along a plane of atomic weakness;
considered an inclusion. (Assignment 10)
Cleavage plane - ANS Plane parallel to a possible crystal face, where a diamond can split
cleanly when struck. (Assignment 7)
Cleaver - ANS A person who cleaves, or splits, a diamond along a cleavage plane. The cleaver
might also be responsible for planning the fashioning of a polished gem. (Assignment 9)
Cleaving - ANS Dividing a diamond into two or more pieces along a cleavage plane.
(Assignment 9)
Cloud (Cld) - ANS Many tightly grouped pinpoints that might be too small to distinguish
individually at 10X but together have a hazy appearance. (Assignment 10)
Color center - ANS Structural defect that influences an object's absorption of light and can
cause its color. (Assignment 12)
4 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
EXAM QUESTIONS AND ANSWERS
GRADED A+ 2025/2026
Abrasion (Abr) - ANS A series of minute nicks along the facet junctions of a fashioned
diamond; gives the edges a white or fuzzy appearance. (Assignment 10)
Adamantine luster - ANS The highest degree of luster possible in a transparent material.
(Assignment 8)
Aggregate - ANS A solid mass of individual, randomly oriented crystals, intergrown or held
together by a natural binding agent. (Assignment 7)
Alluvial deposit - ANS A deposit where gems are eroded from their source rock, then
transported away from the source and further concentrated. (Assignment 5)
Angle of incidence - ANS The angle at which a ray of light strikes a surface, measured from
the normal. (Assignment 8)
Angle of reflection - ANS The angle between the normal and a reflected ray of light.
(Assignment 8)
Annealing - ANS Using heat to stabilize irradiated color in gemstones. (Assignment 12)
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Appraisal - ANS An estimation of the value of an article, usually for insurance purposes.
(Assignment 1)
Average girdle diameter - ANS The result achieved by adding the smallest and largest girdle
measurements of a round brilliant and dividing by two. (Assignment 14)
Bast - ANS Frosted rough diamond. "Bark" in Dutch. (Assignment 9)
Bearded Girdle (BG) - ANS Very small feathers that extend from the girdle surface into the
stone; can result from the cutting process. (Assignment 10)
Belly - ANS The slightly curving center of the long side of a pear, marquise, heart, or oval.
(Assignment 16)
Beneficiation - ANS A commitment to reserve a portion of the resources derived from any
country for the economic development of that country. (Assignment 3)
Best Practices Principles (BPP) - ANS De Beers' formalized commitment of itself and its
sightholders to the highest ethical standards. (Assignment 3)
Blemish - ANS Clarity characteristic that's confined to the surface of a polished gemstone.
(Assignment 10)
Block caving - ANS Underground mining that involves building a concrete-lined tunnel under
an ore deposit, then collecting the ore through openings in the liner. (Assignment 6)
Blocking - ANS Placing the first 17 or 18 facets on a diamond. (Assignment 9)
Bow-tie - ANS A dark area across the center of an elongated brilliant cut. (Assignment 16)
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Brick-and-mortar retailer - ANS A traditional store consisting of walls and a fixed location.
(Assignment 3)
Brightness - ANS The effect of all the diamond's internal and external reflections of white
light. (Assignment 8)
Brilliant cut - ANS A cutting style in which triangular and kite-shaped facets radiate from a
gem's center toward its girdle. (Assignment 16)
Brillianteering - ANS Placement and polishing of the star and upper and lower girdle facets.
(Assignment 9)
Bruise (Br) - ANS A tiny area of impact accompanied by very small, root-like feathers visible at
10X magnification; typically occurs at a facet junction. (Assignment 10)
Bruting - ANS Forming the basic face-up outline of a diamond to prepare it for faceting.
(Assignment 9)
Bulk sampling - ANS Large-scale character sampling. (Assignment 5)
Burn Marks (Brn) - ANS Hazy surface areas that result from excessive heat or from uneven
polishing caused by structural irregularities; also called polish marks or burned facets.
(Assignment 10)
Cavity (Cv) - ANS An angular opening created when part of a feather breaks away.
(Assignment 10)
Central Selling Organisation (CSO) - ANS An agency designed to purchase, sort, evaluate, and
sell rough diamonds. (Assignment 2)
Character sampling - ANS Testing for the size, shape, clarity, and color of the diamonds in a
deposit. (Assignment 5)
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Characteristic color - ANS The basic color of a fancy-colored diamond. (Assignment 13)
Chemical vapor deposition (CVD) - ANS An industrial process adapted to allow growth of
synthetic diamond from carbon-rich gas in thin layers onto a silicon or diamond surface.
(Assignment 19)
Chip (Ch) - ANS A shallow opening caused by damage to the stone's surface; typically occurs
at a girdle edge, facet junction, or culet. (Assignment 10)
Clarity characteristic - ANS Internal or external feature of a gemstone that helps determine its
quality and establish its identity. (Assignment 10)
Cleavage (Cl) - ANS Large, severe, straight break along a plane of atomic weakness;
considered an inclusion. (Assignment 10)
Cleavage plane - ANS Plane parallel to a possible crystal face, where a diamond can split
cleanly when struck. (Assignment 7)
Cleaver - ANS A person who cleaves, or splits, a diamond along a cleavage plane. The cleaver
might also be responsible for planning the fashioning of a polished gem. (Assignment 9)
Cleaving - ANS Dividing a diamond into two or more pieces along a cleavage plane.
(Assignment 9)
Cloud (Cld) - ANS Many tightly grouped pinpoints that might be too small to distinguish
individually at 10X but together have a hazy appearance. (Assignment 10)
Color center - ANS Structural defect that influences an object's absorption of light and can
cause its color. (Assignment 12)
4 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
