GIA Diamond and Diamond
Grading Final Comprehensive
Questions (Frequently Tested)
with Verified Answers Graded
A+
How are gem-quality rough diamonds sorted? - Answer: weight, shape, clarity, and color
What is a downstream segment of the mine to market diamond journey? - Answer: Selling to a
customer via diamond jewelry retail
What describes a larger organization buying and joining smaller companies? - Answer:
Consolidation
What region was the heart of the diamond rush in South Africa? - Answer: Kimberly
What diamond's discovery led to the modern diamond industry? - Answer: The Dudley- star of
South Africa
What is characteristic of minerals? - Answer: Natural inorganic substance with chemical
composition and characteristic structure
What layer is molten? - Answer: Outer core
Where are most diamond deposits found? - Answer: Cratons
Where do most diamonds form and reside? - Answer: Within the mantel keel under cratons
,What is an example of a superdeep diamond? - Answer: Juina
What kind of rock creates a primary diamond deposit? - Answer: Kimberlite
How do geologists locate cratons? - Answer: geological mapping
How does ore removal start in a primary deposit? - Answer: Open-pit mining
What might perovskite in a mineral sample indicate? - Answer: A diamond pipe/source deposit
is nearby
What is the rock that covers a pipe? - Answer: overburden - also called yellow ground due to
yellow color
Which subatomic particle has no electrical charge? - Answer: Neutron
What can the diamond type classification system help to identify? - Answer: Lab-grown
diamonds
What is another name for the cubic system? - Answer: Isometric
What is the surface in a twinned crystal where the diamond's growth direction changes? -
Answer: Twinning plane
What is a rough diamond's value based on? - Answer: Facet gem potential
, What type of radiant energy is found on the electromagnetic spectrum? - Answer: X-ray
What causes steps in a diamond's band gap? - Answer: A constant energy differences. How
much energy an electron requires to move across the gap
What do electrons do when visible light is emitted during luminescence? - Answer: Return to
stable state
What subatomic particles interact with light to produce color? - Answer: Electrons
What does irradiation create when it displaces carbon atoms in the crystal lattice? - Answer:
Vacancies
What is refraction? - Answer: The change in speed and possible change in direction of light as it
travels from one material to another
What is fire in a polished diamond? - Answer: Dispersion
What is a key component of cut quality in a polished diamond? - Answer: Proportion
What is essential for consistent diamond cut grading? - Answer: Spot and diffused fluorescent
lighting
What happens to light rays outside the critical angle cone? - Answer: Reflect interally
What did cutters apply the modern brilliant cut to fancy shapes? - Answer: to maximize profit
from oddly shaped or off color
Grading Final Comprehensive
Questions (Frequently Tested)
with Verified Answers Graded
A+
How are gem-quality rough diamonds sorted? - Answer: weight, shape, clarity, and color
What is a downstream segment of the mine to market diamond journey? - Answer: Selling to a
customer via diamond jewelry retail
What describes a larger organization buying and joining smaller companies? - Answer:
Consolidation
What region was the heart of the diamond rush in South Africa? - Answer: Kimberly
What diamond's discovery led to the modern diamond industry? - Answer: The Dudley- star of
South Africa
What is characteristic of minerals? - Answer: Natural inorganic substance with chemical
composition and characteristic structure
What layer is molten? - Answer: Outer core
Where are most diamond deposits found? - Answer: Cratons
Where do most diamonds form and reside? - Answer: Within the mantel keel under cratons
,What is an example of a superdeep diamond? - Answer: Juina
What kind of rock creates a primary diamond deposit? - Answer: Kimberlite
How do geologists locate cratons? - Answer: geological mapping
How does ore removal start in a primary deposit? - Answer: Open-pit mining
What might perovskite in a mineral sample indicate? - Answer: A diamond pipe/source deposit
is nearby
What is the rock that covers a pipe? - Answer: overburden - also called yellow ground due to
yellow color
Which subatomic particle has no electrical charge? - Answer: Neutron
What can the diamond type classification system help to identify? - Answer: Lab-grown
diamonds
What is another name for the cubic system? - Answer: Isometric
What is the surface in a twinned crystal where the diamond's growth direction changes? -
Answer: Twinning plane
What is a rough diamond's value based on? - Answer: Facet gem potential
, What type of radiant energy is found on the electromagnetic spectrum? - Answer: X-ray
What causes steps in a diamond's band gap? - Answer: A constant energy differences. How
much energy an electron requires to move across the gap
What do electrons do when visible light is emitted during luminescence? - Answer: Return to
stable state
What subatomic particles interact with light to produce color? - Answer: Electrons
What does irradiation create when it displaces carbon atoms in the crystal lattice? - Answer:
Vacancies
What is refraction? - Answer: The change in speed and possible change in direction of light as it
travels from one material to another
What is fire in a polished diamond? - Answer: Dispersion
What is a key component of cut quality in a polished diamond? - Answer: Proportion
What is essential for consistent diamond cut grading? - Answer: Spot and diffused fluorescent
lighting
What happens to light rays outside the critical angle cone? - Answer: Reflect interally
What did cutters apply the modern brilliant cut to fancy shapes? - Answer: to maximize profit
from oddly shaped or off color
