GIA DIAMONDS AND DIAMOND
GRADING FINAL EXAM #2 2025
QUESTIONS AND ANSWERS
London Diamond Syndicate - ANS What group was critical to De Beers's early sales strategy?
Color - ANS How are gem-quality rough diamonds sorted?
Baby Boomers - ANS What generation was first to connect with diamonds as a
representation of lifetime commitment?
India - ANS Where did the diamond industry first start?
Single-channel marketing - ANS What describes the concept of centrally controlled supply,
purchase, promotion, and sales of rough diamonds?
Lower mantle - ANS What mantle layer is most dense?
Will turn into graphite - ANS What happens to diamond if lamproite stalls in the continental
crust?
When a continental and oceanic plate collide - ANS When does subduction occur?
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, High heat and high pressure - ANS How are metamorphic rocks formed?
CLIPPIR diamonds, blue diamonds, Brazil's Junia diamond - ANS What is an example of a
superdeep diamond?
A good sign that a pipe is nearby - ANS What might black spinel in a mineral sample indicate?
Robotic/automated crawlers - ANS What equipment might offshore deep-sea diamond
mining use?
Primary deposits - ANS What deposit type produces most diamonds mined today?
Character sampling - ANS What type of sampling gives an initial idea of diamond quality for a
deposit?
Brazil - ANS Where are rocks and geological structures similar to Africa found due to ancient
connections?
Crystal structure - ANS What is another term for crystal lattice?
Type Ia - ANS What type are most natural diamonds?
Cleavage - ANS What is a smooth, flat break in a crystal parallel to a cleavage plane?
Macle - ANS What is a flat, triangular, twinned diamond crystal?
Intrinsic defect and extrinsic defects - ANS What types of point defects are found in
2
diamonds?
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, Color center - ANS What influences light absorption, resulting in bodycolor?
Hydrogen-related defects - ANS What trace element can cause a violet color in diamonds?
Lower - ANS How does the energy emitted by a gem compare to the energy it absorbs?
White light - ANS What type of light combines all the colors in the visible spectrum?
Nitrogen defects - ANS What is the most common cause of yellow color in diamonds?
Cutting - ANS What controls light path length within a diamond?
Luster - ANS What term describes a gemstone's surface in reflected light?
Fire - ANS What describes the flashes of spectral colors seen in a polished diamond?
Determine which proportion combinations create the most attractive light performance -
ANS What was the main goal of research in developing the GIA Cut Grading System?
Measured btwn the normal and the reflected light - ANS What best describes the angle of
incidence?
Cleaving - ANS What process splits diamond rough along its cleavage plane?
Strain - ANS What do cutters evaluate to determine when to use a scaife for coning?
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@COPYRIGHT SIRJOEL 2025/2026
GRADING FINAL EXAM #2 2025
QUESTIONS AND ANSWERS
London Diamond Syndicate - ANS What group was critical to De Beers's early sales strategy?
Color - ANS How are gem-quality rough diamonds sorted?
Baby Boomers - ANS What generation was first to connect with diamonds as a
representation of lifetime commitment?
India - ANS Where did the diamond industry first start?
Single-channel marketing - ANS What describes the concept of centrally controlled supply,
purchase, promotion, and sales of rough diamonds?
Lower mantle - ANS What mantle layer is most dense?
Will turn into graphite - ANS What happens to diamond if lamproite stalls in the continental
crust?
When a continental and oceanic plate collide - ANS When does subduction occur?
1
Page
@COPYRIGHT SIRJOEL 2025/2026
, High heat and high pressure - ANS How are metamorphic rocks formed?
CLIPPIR diamonds, blue diamonds, Brazil's Junia diamond - ANS What is an example of a
superdeep diamond?
A good sign that a pipe is nearby - ANS What might black spinel in a mineral sample indicate?
Robotic/automated crawlers - ANS What equipment might offshore deep-sea diamond
mining use?
Primary deposits - ANS What deposit type produces most diamonds mined today?
Character sampling - ANS What type of sampling gives an initial idea of diamond quality for a
deposit?
Brazil - ANS Where are rocks and geological structures similar to Africa found due to ancient
connections?
Crystal structure - ANS What is another term for crystal lattice?
Type Ia - ANS What type are most natural diamonds?
Cleavage - ANS What is a smooth, flat break in a crystal parallel to a cleavage plane?
Macle - ANS What is a flat, triangular, twinned diamond crystal?
Intrinsic defect and extrinsic defects - ANS What types of point defects are found in
2
diamonds?
Page
@COPYRIGHT SIRJOEL 2025/2026
, Color center - ANS What influences light absorption, resulting in bodycolor?
Hydrogen-related defects - ANS What trace element can cause a violet color in diamonds?
Lower - ANS How does the energy emitted by a gem compare to the energy it absorbs?
White light - ANS What type of light combines all the colors in the visible spectrum?
Nitrogen defects - ANS What is the most common cause of yellow color in diamonds?
Cutting - ANS What controls light path length within a diamond?
Luster - ANS What term describes a gemstone's surface in reflected light?
Fire - ANS What describes the flashes of spectral colors seen in a polished diamond?
Determine which proportion combinations create the most attractive light performance -
ANS What was the main goal of research in developing the GIA Cut Grading System?
Measured btwn the normal and the reflected light - ANS What best describes the angle of
incidence?
Cleaving - ANS What process splits diamond rough along its cleavage plane?
Strain - ANS What do cutters evaluate to determine when to use a scaife for coning?
3
Page
@COPYRIGHT SIRJOEL 2025/2026
