GIA Diamonds & Diamond Grading Week
3 Practice Questions and Answers
1. What changes in the proportions create distortions in appearance visible to the
observer?
2. Which proportions are attractive or unattractive to most observers? - ANSWER-For
the cut grading system to be reliable, predictive, & practical, what 2 questions must be
answered?
17 or 18 facets (crown, main pavilion facets, table, and/or culet) - ANSWER-How many
facets are made during blocking?
a combination of the colors in the visible spectrum (red, orange, yellow, green, blue &
violet) - ANSWER-What is white light?
a flat break parallel to a cleavage plane - ANSWER-What would a well-placed blow
cause to a cleavage plane?
a form of radiant energy or radiation; a combination of electric and magnetic
(electromagnetic) energies that travels in waves - ANSWER-What is light?
aggregated nitrogen impurities - ANSWER-What do type Ia diamonds contain?
aggregated pairs of nitrogen - ANSWER-What do type IaA "A centers" have?
an absorption band centered at approximately 480 nm in the visible spectrum -
ANSWER-What defect is primarily responsible for orange bodycolor in type Ia
diamonds?
an absorption band centered at approximately 550 nm - ANSWER-Approximately in the
visible spectrum, where is the main cause of PINK-to-red, purple, and brown colors in
diamonds?
an insulator, so diamonds that lack color centers are colorless because they do not
absorb visible light - ANSWER-In theory, what is a defect-free diamond?
areas of green or brown radiation damage on their surfaces, seen as "spots" or patches
of color, and referred to as staining - ANSWER-What do most naturally irradiated
diamonds have?
atom - ANSWER-the basic structural unit of all matter
become brownish - ANSWER-What happens to warm hues (orange, red, & yellow)
when saturation drops?
, become grayish - ANSWER-What happens to cool hues (blue, blue-green, &violet)
when saturation drops?
between the incident ray and the normal - ANSWER-How is the angle of incidence
measured?
blocking - ANSWER-What must be done carefully to establish the diamond's basic
symmetry?
bounces off surrounding walls & furnishings, so the light that strikes the diamond comes
from all angles - ANSWER-How does diffused lighting act with a diamond?
brightness, scintillation, & fire - ANSWER-What are the components of the cut quality's
face-up appearance?
by dark inclusions of graphite, sulfide, magnetite, hematite, or other iron-bearing
minerals - ANSWER-How are natural black diamonds usually colored?
caused by dislocation; often concentrated within parallel narrow bands (colored
lamellae) - ANSWER-How do pink, red, purple, and brown diamonds obtain their color?
cleavage - ANSWER-a smooth, flat break in a crystal parallel to a cleavage plane
cleavage planes - ANSWER-directions in which there are fewer carbon atoms, with
more space between them, than in others; planar surface along which a mineral tends
to break due to atomic weakness
cleaving - ANSWER-the process of dividing rough diamond along its cleavage planes
color center - ANSWER-a defect that can influence an object's absorption of visible light
to cause its color
colored lamellae - ANSWER-closely spaced grain lines where color concentrates,
resulting from deformation
Colorless = DEF
Near Colorless = GHIJ
Faint = KLM
Very Light = N, O-P, Q-R
Light = S-T, U-V, W-X, Y-Z - ANSWER-What are the descriptors and the letters
associated with them on the GIA color scale?
coning - ANSWER-What is commonly done on round-shape diamonds to form the
pavilion angles and reduces potential damage to strained stones?
3 Practice Questions and Answers
1. What changes in the proportions create distortions in appearance visible to the
observer?
2. Which proportions are attractive or unattractive to most observers? - ANSWER-For
the cut grading system to be reliable, predictive, & practical, what 2 questions must be
answered?
17 or 18 facets (crown, main pavilion facets, table, and/or culet) - ANSWER-How many
facets are made during blocking?
a combination of the colors in the visible spectrum (red, orange, yellow, green, blue &
violet) - ANSWER-What is white light?
a flat break parallel to a cleavage plane - ANSWER-What would a well-placed blow
cause to a cleavage plane?
a form of radiant energy or radiation; a combination of electric and magnetic
(electromagnetic) energies that travels in waves - ANSWER-What is light?
aggregated nitrogen impurities - ANSWER-What do type Ia diamonds contain?
aggregated pairs of nitrogen - ANSWER-What do type IaA "A centers" have?
an absorption band centered at approximately 480 nm in the visible spectrum -
ANSWER-What defect is primarily responsible for orange bodycolor in type Ia
diamonds?
an absorption band centered at approximately 550 nm - ANSWER-Approximately in the
visible spectrum, where is the main cause of PINK-to-red, purple, and brown colors in
diamonds?
an insulator, so diamonds that lack color centers are colorless because they do not
absorb visible light - ANSWER-In theory, what is a defect-free diamond?
areas of green or brown radiation damage on their surfaces, seen as "spots" or patches
of color, and referred to as staining - ANSWER-What do most naturally irradiated
diamonds have?
atom - ANSWER-the basic structural unit of all matter
become brownish - ANSWER-What happens to warm hues (orange, red, & yellow)
when saturation drops?
, become grayish - ANSWER-What happens to cool hues (blue, blue-green, &violet)
when saturation drops?
between the incident ray and the normal - ANSWER-How is the angle of incidence
measured?
blocking - ANSWER-What must be done carefully to establish the diamond's basic
symmetry?
bounces off surrounding walls & furnishings, so the light that strikes the diamond comes
from all angles - ANSWER-How does diffused lighting act with a diamond?
brightness, scintillation, & fire - ANSWER-What are the components of the cut quality's
face-up appearance?
by dark inclusions of graphite, sulfide, magnetite, hematite, or other iron-bearing
minerals - ANSWER-How are natural black diamonds usually colored?
caused by dislocation; often concentrated within parallel narrow bands (colored
lamellae) - ANSWER-How do pink, red, purple, and brown diamonds obtain their color?
cleavage - ANSWER-a smooth, flat break in a crystal parallel to a cleavage plane
cleavage planes - ANSWER-directions in which there are fewer carbon atoms, with
more space between them, than in others; planar surface along which a mineral tends
to break due to atomic weakness
cleaving - ANSWER-the process of dividing rough diamond along its cleavage planes
color center - ANSWER-a defect that can influence an object's absorption of visible light
to cause its color
colored lamellae - ANSWER-closely spaced grain lines where color concentrates,
resulting from deformation
Colorless = DEF
Near Colorless = GHIJ
Faint = KLM
Very Light = N, O-P, Q-R
Light = S-T, U-V, W-X, Y-Z - ANSWER-What are the descriptors and the letters
associated with them on the GIA color scale?
coning - ANSWER-What is commonly done on round-shape diamonds to form the
pavilion angles and reduces potential damage to strained stones?
