GIA DIAMONDS AND DIAMOND GRADING FINAL EXAM NEWEST
2024-2025 ACTUAL EXAM COMPLETE 200 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED)
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
, How does laser sawing increase weight retention? - (answer) 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? - (answer) table cut
What is the goal of coning? - (answer) to form the pavillion angle
What polishing step forms the main crown and pavillion facets? - (answer) Blocking
When did manufactures first market near-colorless to colorless gem-quality lab-grown diamonds? -
(answer) 1990s
What does 'CVD' stand for? - (answer) Chemical Vapor Deposition
What does 'HPHT' production of lab-grown diamonds require? - (answer) Carbon source, heating
element, metal catalyst, seed crystal, temperature gradient
Where are CVD diamonds grown? - (answer) In a heated mixture of hydrocarbon gas and excess
hydrogen gas
What shape can metallic inclusions takes in HPHT diamond? - (answer) Feather and chips / rounded,
elongated, or irregularly shaped
How do gemological laboratories report a drill hole? - (answer) clarity characteristic
How does the refractive index (RI) of a fracture filling compare to diamonds? - (answer) Similar
How does HPHT processing of type II diamonds enhance bodycolor? - (answer) Become near-
colorless to colorless / D-H
2024-2025 ACTUAL EXAM COMPLETE 200 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED)
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
, How does laser sawing increase weight retention? - (answer) 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? - (answer) table cut
What is the goal of coning? - (answer) to form the pavillion angle
What polishing step forms the main crown and pavillion facets? - (answer) Blocking
When did manufactures first market near-colorless to colorless gem-quality lab-grown diamonds? -
(answer) 1990s
What does 'CVD' stand for? - (answer) Chemical Vapor Deposition
What does 'HPHT' production of lab-grown diamonds require? - (answer) Carbon source, heating
element, metal catalyst, seed crystal, temperature gradient
Where are CVD diamonds grown? - (answer) In a heated mixture of hydrocarbon gas and excess
hydrogen gas
What shape can metallic inclusions takes in HPHT diamond? - (answer) Feather and chips / rounded,
elongated, or irregularly shaped
How do gemological laboratories report a drill hole? - (answer) clarity characteristic
How does the refractive index (RI) of a fracture filling compare to diamonds? - (answer) Similar
How does HPHT processing of type II diamonds enhance bodycolor? - (answer) Become near-
colorless to colorless / D-H
