GIA Diamonds and Diamond grading
Comprehensive Questions (Frequently
Tested) with Verified Answers Graded
A+
Beneficiation - Answer: A commitment to reserve a portion of the resources derived from any
country for the economic development of that country.
Blemish - 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 - Answer: A shared, unalterable ledger used to record transactions and track assets
through a supply chain or business network.
Blocking - Answer: Placing the first 17 or 18 facets on a diamond, including the crown and
pavilion main facets, table, and sometimes a culet.
Bort - 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 - Answer: A dark area across the center of an elongated brilliant cut.
Brightfield illumination - Answer: Lighting a diamondfrom below to create a bright background.
,Brightness - Answer: The effect of all the diamond's internal and external reflections of white
light.
Brilliant cut - Answer: Cutting style with triangular or kite-shaped facets that radiate from the
center toward the girdle.
Brillianteering - Answer: Placement and polishing of the star and upper and lower girdle facets.
Bruting - Answer: Forming the basic face-up outline of a round or rounded shape diamond to
prepare it for faceting.
Bulk sampling - Answer: Large-scale character sampling.
Carbonado - Answer: An aggregate of many randomly oriented interlocking tiny diamond
crystals that is the toughest form of diamond.
Carbonate - Answer: A class of chemical compounds that contain carbon and oxygen.
Catalyst - Answer: A substance that increases the rate of a chemical reaction.
Cave mining - Answer: An underground mining technique in which orebody is drilled beneath
the surface, loosened, and collected as it falls.
Central Selling Organisation (CSO) - Answer: An agency designed to purchase, sort, evaluate,
and sell rough diamonds.
Character sampling - Answer: Testing for the size, shape, clarity, and color of the diamonds in a
deposit.
, Characteristic color - Answer: The basic face-up color of a colored diamond.
Clarity characteristic - Answer: Internal or external feature of a gemstone that helps determine
its quality.
Cleavage - Answer: A smooth, flat break in a gemstone parallel to planes of atomic weakness.
Cleavage plane - Answer: Plane parallel to a possible crystal face, where a diamond can split
cleanly when struck.
Cleaving - Answer: Dividing a diamond into two or more pieces along a cleavage plane.
CLIPPIR diamonds - Answer: Cullinan-like, Large, Inclusion-Poor, Pure, Irregular, and Resorbed
diamond.
Color center - 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 - Answer: Closely spaced grain lines where color concentrates.
Coning - Answer: The process of forming the pavilion angle by gradually polishing off the extra
material at different angles.
Consignment - Answer: A selection of goods loaned to a dealer by another wholesaler or a gem
cutter.
Comprehensive Questions (Frequently
Tested) with Verified Answers Graded
A+
Beneficiation - Answer: A commitment to reserve a portion of the resources derived from any
country for the economic development of that country.
Blemish - 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 - Answer: A shared, unalterable ledger used to record transactions and track assets
through a supply chain or business network.
Blocking - Answer: Placing the first 17 or 18 facets on a diamond, including the crown and
pavilion main facets, table, and sometimes a culet.
Bort - 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 - Answer: A dark area across the center of an elongated brilliant cut.
Brightfield illumination - Answer: Lighting a diamondfrom below to create a bright background.
,Brightness - Answer: The effect of all the diamond's internal and external reflections of white
light.
Brilliant cut - Answer: Cutting style with triangular or kite-shaped facets that radiate from the
center toward the girdle.
Brillianteering - Answer: Placement and polishing of the star and upper and lower girdle facets.
Bruting - Answer: Forming the basic face-up outline of a round or rounded shape diamond to
prepare it for faceting.
Bulk sampling - Answer: Large-scale character sampling.
Carbonado - Answer: An aggregate of many randomly oriented interlocking tiny diamond
crystals that is the toughest form of diamond.
Carbonate - Answer: A class of chemical compounds that contain carbon and oxygen.
Catalyst - Answer: A substance that increases the rate of a chemical reaction.
Cave mining - Answer: An underground mining technique in which orebody is drilled beneath
the surface, loosened, and collected as it falls.
Central Selling Organisation (CSO) - Answer: An agency designed to purchase, sort, evaluate,
and sell rough diamonds.
Character sampling - Answer: Testing for the size, shape, clarity, and color of the diamonds in a
deposit.
, Characteristic color - Answer: The basic face-up color of a colored diamond.
Clarity characteristic - Answer: Internal or external feature of a gemstone that helps determine
its quality.
Cleavage - Answer: A smooth, flat break in a gemstone parallel to planes of atomic weakness.
Cleavage plane - Answer: Plane parallel to a possible crystal face, where a diamond can split
cleanly when struck.
Cleaving - Answer: Dividing a diamond into two or more pieces along a cleavage plane.
CLIPPIR diamonds - Answer: Cullinan-like, Large, Inclusion-Poor, Pure, Irregular, and Resorbed
diamond.
Color center - 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 - Answer: Closely spaced grain lines where color concentrates.
Coning - Answer: The process of forming the pavilion angle by gradually polishing off the extra
material at different angles.
Consignment - Answer: A selection of goods loaned to a dealer by another wholesaler or a gem
cutter.
