GIA Diamonds and Diamond Grading Final Exam #2 –
Questions & Complete Solutions
What group was critical to De Beers's early sales strategy? Right Ans -
London Diamond Syndicate
How are gem-quality rough diamonds sorted? Right Ans - Color
What generation was first to connect with diamonds as a representation of
lifetime commitment? Right Ans - Baby Boomers
Where did the diamond industry first start? Right Ans - India
What describes the concept of centrally controlled supply, purchase,
promotion, and sales of rough diamonds? Right Ans - Single-channel
marketing
What mantle layer is most dense? Right Ans - Lower mantle
What happens to diamond if lamproite stalls in the continental crust? Right
Ans - Will turn into graphite
When does subduction occur? Right Ans - When a continental and oceanic
plate collide
How are metamorphic rocks formed? Right Ans - High heat and high
pressure
What is an example of a superdeep diamond? Right Ans - CLIPPIR
diamonds, blue diamonds, Brazil's Junia diamond
What might black spinel in a mineral sample indicate? Right Ans - A good
sign that a pipe is nearby
What equipment might offshore deep-sea diamond mining use? Right Ans -
Robotic/automated crawlers
,What deposit type produces most diamonds mined today? Right Ans -
Primary deposits
What type of sampling gives an initial idea of diamond quality for a deposit?
Right Ans - Character sampling
Where are rocks and geological structures similar to Africa found due to
ancient connections? Right Ans - Brazil
What is another term for crystal lattice? Right Ans - Crystal structure
What type are most natural diamonds? Right Ans - Type Ia
What is a smooth, flat break in a crystal parallel to a cleavage plane? Right
Ans - Cleavage
What is a flat, triangular, twinned diamond crystal? Right Ans - Macle
What types of point defects are found in diamonds? Right Ans - Intrinsic
defect and extrinsic defects
What influences light absorption, resulting in bodycolor? Right Ans - Color
center
What trace element can cause a violet color in diamonds? Right Ans -
Hydrogen-related defects
How does the energy emitted by a gem compare to the energy it absorbs?
Right Ans - Lower
What type of light combines all the colors in the visible spectrum? Right
Ans - White light
What is the most common cause of yellow color in diamonds? Right Ans -
Nitrogen defects
What controls light path length within a diamond? Right Ans - Cutting
, What term describes a gemstone's surface in reflected light? Right Ans -
Luster
What describes the flashes of spectral colors seen in a polished diamond?
Right Ans - Fire
What was the main goal of research in developing the GIA Cut Grading
System? Right Ans - Determine which proportion combinations create the
most attractive light performance
What best describes the angle of incidence? Right Ans - Measured btwn the
normal and the reflected light
What process splits diamond rough along its cleavage plane? Right Ans -
Cleaving
What do cutters evaluate to determine when to use a scaife for coning?
Right Ans - Strain
What made true round-shaped diamonds possible? Right Ans - Bruting
What was the prototype of the modern round brilliant cut? Right Ans - Old
European cut
What does a dop do? Right Ans - Holds/secures a diamond in place
What does HPHT stand for? Right Ans - High pressure, high temperature
What rough form does NOT appear in natural diamonds Right Ans -
Cuboctahedrons
What diamond type can be created by the HPHT method? Right Ans - Type
1b
What diamonds have strain pattern and intensity similar to natural
diamonds? Right Ans - CVD lab-grown diamonds
When should the origin of a lab-grown diamond be disclosed? Right Ans -
At every step
Questions & Complete Solutions
What group was critical to De Beers's early sales strategy? Right Ans -
London Diamond Syndicate
How are gem-quality rough diamonds sorted? Right Ans - Color
What generation was first to connect with diamonds as a representation of
lifetime commitment? Right Ans - Baby Boomers
Where did the diamond industry first start? Right Ans - India
What describes the concept of centrally controlled supply, purchase,
promotion, and sales of rough diamonds? Right Ans - Single-channel
marketing
What mantle layer is most dense? Right Ans - Lower mantle
What happens to diamond if lamproite stalls in the continental crust? Right
Ans - Will turn into graphite
When does subduction occur? Right Ans - When a continental and oceanic
plate collide
How are metamorphic rocks formed? Right Ans - High heat and high
pressure
What is an example of a superdeep diamond? Right Ans - CLIPPIR
diamonds, blue diamonds, Brazil's Junia diamond
What might black spinel in a mineral sample indicate? Right Ans - A good
sign that a pipe is nearby
What equipment might offshore deep-sea diamond mining use? Right Ans -
Robotic/automated crawlers
,What deposit type produces most diamonds mined today? Right Ans -
Primary deposits
What type of sampling gives an initial idea of diamond quality for a deposit?
Right Ans - Character sampling
Where are rocks and geological structures similar to Africa found due to
ancient connections? Right Ans - Brazil
What is another term for crystal lattice? Right Ans - Crystal structure
What type are most natural diamonds? Right Ans - Type Ia
What is a smooth, flat break in a crystal parallel to a cleavage plane? Right
Ans - Cleavage
What is a flat, triangular, twinned diamond crystal? Right Ans - Macle
What types of point defects are found in diamonds? Right Ans - Intrinsic
defect and extrinsic defects
What influences light absorption, resulting in bodycolor? Right Ans - Color
center
What trace element can cause a violet color in diamonds? Right Ans -
Hydrogen-related defects
How does the energy emitted by a gem compare to the energy it absorbs?
Right Ans - Lower
What type of light combines all the colors in the visible spectrum? Right
Ans - White light
What is the most common cause of yellow color in diamonds? Right Ans -
Nitrogen defects
What controls light path length within a diamond? Right Ans - Cutting
, What term describes a gemstone's surface in reflected light? Right Ans -
Luster
What describes the flashes of spectral colors seen in a polished diamond?
Right Ans - Fire
What was the main goal of research in developing the GIA Cut Grading
System? Right Ans - Determine which proportion combinations create the
most attractive light performance
What best describes the angle of incidence? Right Ans - Measured btwn the
normal and the reflected light
What process splits diamond rough along its cleavage plane? Right Ans -
Cleaving
What do cutters evaluate to determine when to use a scaife for coning?
Right Ans - Strain
What made true round-shaped diamonds possible? Right Ans - Bruting
What was the prototype of the modern round brilliant cut? Right Ans - Old
European cut
What does a dop do? Right Ans - Holds/secures a diamond in place
What does HPHT stand for? Right Ans - High pressure, high temperature
What rough form does NOT appear in natural diamonds Right Ans -
Cuboctahedrons
What diamond type can be created by the HPHT method? Right Ans - Type
1b
What diamonds have strain pattern and intensity similar to natural
diamonds? Right Ans - CVD lab-grown diamonds
When should the origin of a lab-grown diamond be disclosed? Right Ans -
At every step
