GIA Diamond and Diamonds Grading
Final questions and answers
How are gem-quality rough diamonds sorted?✔✔weight, shape, clarity, and color
What is a downstream segment of the mine to market diamond journey?✔✔Selling
to a customer via diamond jewelry retail
What describes a larger organization buying and joining smaller
companies?✔✔Consolidation
What region was the heart of the diamond rush in South Africa?✔✔Kimberly
What diamond's discovery led to the modern diamond industry?✔✔The Dudley- star
of South Africa
What is characteristic of minerals?✔✔Natural inorganic substance with chemical
composition and characteristic structure
What layer is molten?✔✔Outer core
Where are most diamond deposits found?✔✔Cratons
Where do most diamonds form and reside?✔✔Within the mantel keel under cratons
What is an example of a superdeep diamond?✔✔Juina
What kind of rock creates a primary diamond deposit?✔✔Kimberlite
How do geologists locate cratons?✔✔geological mapping
How does ore removal start in a primary deposit?✔✔Open-pit mining
What might perovskite in a mineral sample indicate?✔✔A diamond pipe/source
deposit is nearby
What is the rock that covers a pipe?✔✔overburden - also called yellow ground due
to yellow color
Which subatomic particle has no electrical charge?✔✔Neutron
What can the diamond type classification system help to identify?✔✔Lab-grown
diamonds
What is another name for the cubic system?✔✔Isometric
, What is the surface in a twinned crystal where the diamond's growth direction
changes?✔✔Twinning plane
What is a rough diamond's value based on?✔✔Facet gem potential
What type of radiant energy is found on the electromagnetic spectrum?✔✔X-ray
What causes steps in a diamond's band gap?✔✔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?✔✔Return to
stable state
What subatomic particles interact with light to produce color?✔✔Electrons
What does irradiation create when it displaces carbon atoms in the crystal
lattice?✔✔Vacancies
What is refraction?✔✔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?✔✔Dispersion
What is a key component of cut quality in a polished diamond?✔✔Proportion
What is essential for consistent diamond cut grading?✔✔Spot and diffused
fluorescent lighting
What happens to light rays outside the critical angle cone?✔✔Reflect interally
What did cutters apply the modern brilliant cut to fancy shapes?✔✔to maximize profit
from oddly shaped or off color
How does laser sawing increase weight retention?✔✔They are computerized, so
they are quicker and more precise. "Pie or Scoop sawing". That will save the weight
retention
What early cut introduced the culet?✔✔table cut
What is the goal of coning?✔✔to form the pavillion angle
What polishing step forms the main crown and pavillion facets?✔✔Blocking
When did manufactures first market near-colorless to colorless gem-quality lab-
grown diamonds?✔✔1990s
What does 'CVD' stand for?✔✔Chemical Vapor Deposition
Final questions and answers
How are gem-quality rough diamonds sorted?✔✔weight, shape, clarity, and color
What is a downstream segment of the mine to market diamond journey?✔✔Selling
to a customer via diamond jewelry retail
What describes a larger organization buying and joining smaller
companies?✔✔Consolidation
What region was the heart of the diamond rush in South Africa?✔✔Kimberly
What diamond's discovery led to the modern diamond industry?✔✔The Dudley- star
of South Africa
What is characteristic of minerals?✔✔Natural inorganic substance with chemical
composition and characteristic structure
What layer is molten?✔✔Outer core
Where are most diamond deposits found?✔✔Cratons
Where do most diamonds form and reside?✔✔Within the mantel keel under cratons
What is an example of a superdeep diamond?✔✔Juina
What kind of rock creates a primary diamond deposit?✔✔Kimberlite
How do geologists locate cratons?✔✔geological mapping
How does ore removal start in a primary deposit?✔✔Open-pit mining
What might perovskite in a mineral sample indicate?✔✔A diamond pipe/source
deposit is nearby
What is the rock that covers a pipe?✔✔overburden - also called yellow ground due
to yellow color
Which subatomic particle has no electrical charge?✔✔Neutron
What can the diamond type classification system help to identify?✔✔Lab-grown
diamonds
What is another name for the cubic system?✔✔Isometric
, What is the surface in a twinned crystal where the diamond's growth direction
changes?✔✔Twinning plane
What is a rough diamond's value based on?✔✔Facet gem potential
What type of radiant energy is found on the electromagnetic spectrum?✔✔X-ray
What causes steps in a diamond's band gap?✔✔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?✔✔Return to
stable state
What subatomic particles interact with light to produce color?✔✔Electrons
What does irradiation create when it displaces carbon atoms in the crystal
lattice?✔✔Vacancies
What is refraction?✔✔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?✔✔Dispersion
What is a key component of cut quality in a polished diamond?✔✔Proportion
What is essential for consistent diamond cut grading?✔✔Spot and diffused
fluorescent lighting
What happens to light rays outside the critical angle cone?✔✔Reflect interally
What did cutters apply the modern brilliant cut to fancy shapes?✔✔to maximize profit
from oddly shaped or off color
How does laser sawing increase weight retention?✔✔They are computerized, so
they are quicker and more precise. "Pie or Scoop sawing". That will save the weight
retention
What early cut introduced the culet?✔✔table cut
What is the goal of coning?✔✔to form the pavillion angle
What polishing step forms the main crown and pavillion facets?✔✔Blocking
When did manufactures first market near-colorless to colorless gem-quality lab-
grown diamonds?✔✔1990s
What does 'CVD' stand for?✔✔Chemical Vapor Deposition
