Study Questions for Sections 8 & 9
8.01
1. A diamond imitation and lab-grown diamond are the same.
a. True
b. False
2. 2. Lab-grown diamond has similar but not exactly the same atomic structure.
a. True
b. False
3. 3. Lab-grown diamond and cubic zirconia are the same.
a. True
b. False
4. Lab-grown diamond is a diamond simulant.
a. True
b. False
5. Lab-grown diamond has the same growth pattern as natural diamond.
a. True
b. False
8.02
1. H. Tracy Hall with General Electric, made the first reproducible HPHT (high pressure high temperature) synthetic diamond (lab-grown diamond) in…
a. 1953
b. 1954
c. 1970
2. The first gem quality synthetic diamond was created by General Electric in…
a. 1954
b. 1970
c. the 1980s
3. The first gem quality synthetic diamond was very cost effective.
a. True
b. False
4. Further Improvements in synthetic diamond technology since the 1970s were initiated by companies including:
a. General Electric
b. Sumitomo of Japan
c. All of the above
d. None of the above
5. In which year was the first gem quality High-Pressure High-Temperature (HPHT) synthetic diamond produced by General Electric?
a. 1954
b. 1970
c. 1980
d. None of the above
6. The first gem quality diamonds contained nitrogen which rendered which color?
a. White
b. Green
c. Blue
d. Yellow
e. None of the above
7. What does CVD stand for?
a. Carbon Vapor Deposition
b. Chemically Visual Deposition
c. Chemical Vapor Deposition
d. Chemical Vapor Deposit
e. None of the above
8. What does HPHT stand for?
a. Hyper Pressure Hyper Temperature
b. Hydrogen Photon Helium Tempered
c. High Pressure High Temperature
d. High Pressure Hydrogen Treatment
e. None of the above
9. In which decade were CVD diamonds available for jewelry purposes?
a. 1970s
b. 1980s
c. 1990s
d. None of the above
10. In 2007 GIA (Gemological Institute of America) started issuing synthetic diamond reports for what purpose?
a. Color and Clarity Grading
b. Cut Grading
c. Identification, Color, Clarity, Cut and Carat Weight
d. Identification
e. All of the above
f. None of the above
11. By 2019 GIA changed its terminology to "laboratory-grown" and the reports now included:
a. Color and Clarity Grading
b. Cut Grading
c. Identification, Color, Clarity, Cut and Carat Weight
d. Identification
e. All of the above
f. None of the above
12. In 2018 the FTC (Federal Trade Commission) updated their guidelines urging jewelers to use the term?
a. Lab-Created or Laboratory-Grown
b. Synthetic
c. Real Diamond
d. Diamond Simulant
e. None of the above
f. All of the above
8.03
1. Lab-Grown diamond prices have continued to rise in price?
a. True
b. False
2. Lab-Grown diamond creation is typically more expensive than mining natural diamonds.
a. True
b. False
3. Lab-Grown diamond supply like natural precious gemstones and natural diamonds, may be affected by:
a. Tariffs
b. Rising business taxes
c. Natural disasters
d. All of the above
4. Which lab-grown diamond requires more energy to produce?
a. CVD
b. HPHT
c. No difference in energy cost
5. At this writing (2026) is there an oversupply or undersupply of lab-grown diamonds.
a. Oversupply
b. Undersupply
c. Neither
6. Lab-grown diamonds have had very little effect on natural diamond prices.
a. True
b. False
8.04
1. Lab-grown diamonds are also known as synthetic, cultured, created and man-made diamond?
a. True
b. False
2. How many growth directions does a high-pressure high-temperature (HPHT) rough diamond crystal have?
a. 1
b. 8
c. 12
d. 14
3. What type of seed is used in the HPHT growth process?
a. Iron, cobalt or nickel
b. Moissanite
c. Silica
d. None of the above
4. What would a typical carbon source be in the HPHT growth process?
a. Lead
b. Graphite
c. Silica
d. Diamond
e. None of the above
f. All of the above
5. What is a typical metal catalyst used in the HPHT growth process?
a. Iron
b. Nickel
c. Cobalt
d. All of the above
e. None of the above
6. What is the purpose of the substrate in the CVD (Chemical Vapor Deposition) growth process?
a. It is the seed
b. It is the stage or platform to grow the CVD diamond on
c. It is the chamber the CVD diamond grows within
d. All of the above
e. None of the above
7. Which of the following does the CVD (Chemical Vapor Deposition) typically employ to create the substrate?
a. Iridium
b. Lead
c. Silver
d. All of the above
e. None of the above
8. What other material can be used as a substrate in the CVD growth method?
a. A grown HPHT crystal polished and cleaned
b. 20mm square tempered glass
c. 10mm square carbon gallium wafer
d. All of the above
e. None of the above
9. Which two gases are typically used to create white CVD diamonds?
a. Methane and hydrogen
b. Methane and helium
c. Carbon dioxide and hydrogen
d. None of the above
10. What other gases can be introduced into the CVD growth chamber to produce fancy colors such as blue or yellow.
a. Carbon dioxide and nitrogen
b. Methane and boron
c. Nitrogen and boron
d. None of the above
11. The temperature achieved in the CVD growth process exceeds that of the HPHT growth process.
a. True
b. False
12. What does the gas-filled CVD growth chamber create when heat and microwave energy is introduced.
a. Charged hydrogen
b. Charged plasma
c. Charged helium
d. All of the above
e. None of the above
13. Homoepitaxial growth is…
a. the CVD process of growing crystalline layers upon an identical material
b. the CVD process of growing crystalline layers upon a completely different material
c. the HPHT process of growing crystalline layers on an ion substrate
d. None of the above
14. Polycrystalline diamonds are…
a. the CVD process of growing multiple single crystal diamonds in one chamber.
b. the HPHT process of growing multiple single crystal diamonds in one chamber.
c. a series of non-single-crystal diamonds.
d. None of the above
15. All lab-grown diamonds are laser inscribed.
a. True
b. False
16. What are polycrystalline diamonds?
a. The result of growing multiple CVD single crystal diamonds in one chamber.
b. The result of growing multiple HPHT single crystal diamonds in one chamber.
c. A series of non-single-crystal diamonds as one structure.
d. None of the above
17. What are the five subdivided diamond types?
a. Type IaA, Type IaB, Type Ib, Type IIa, and Type IIbc.
b. Type IaA, Type IaB, Type Ib, Type IIa, and Type IIb.
c. Type IaA, Type IaB, Type Ib, Type IIIa, and Type IIb.
d. None of the above
18. Which instrument is used to test the light absorption properties in determining the diamond type?
a. Refractometer
b. Spectrometer
c. Gemology microscope
d. None of the above
19. If present, will a lab-grown or natural diamond typically show more intense fluorescence when exposed to long-wave ultraviolet light?
a. Lab Grown
b. Natural
c. About the same
20. Is short-wave ultraviolet light commonly used in natural diamond identification?
a. Yes
b. No
21. What is phosphorescence in diamond?
a. Intense green fluorescence.
b. The lingering glow after radiation exposure especially in natural green diamond.
c. The lingering glow after long-wave or short-wave ultraviolet exposure.
22. Is ultraviolet testing conclusive in determining a lab-grown diamond identification?
a. Yes
b. No
23. Is phosphorescence more common in lab-grown or natural diamond?
a. It’s very rare in both lab-grown and natural diamond.
b. It’s much more common in lab-grown diamond.
c. It’s much more common in natural diamond.
24. What is visible absorption in diamond?
a. It is the light that is absorbed causing refraction.
b. It is the light that is absorbed causing a colorless diamond.
c. It is the light that is absorbed by defects such as nitrogen or structural anomalies.
d. None of the above.
25. Typically, what color is visible when blue light is absorbed in a diamond?
a. Blue fluorescence
b. Only blue
c. Blue or brown
d. Yellow or blue
e. Yellow or brown
f. Only yellow
26. Any presence of nitrogen atoms cause a yellow hue.
a. True
b. False
27. Why is it so important to determine the diamond type in lab-grown and natural diamond identification?
a. Almost all Type I diamonds are lab-grown.
b. Almost all Type II diamonds are natural.
c. Almost all lab-grown diamonds are Type II.
d. None of the above.
28. It is conclusive to determine the diamond type alone to differentiate lab-grown and natural diamond.
a. True
b. False
29. Lab-grown diamonds are generally type IIa.
a. True
b. False
30. What is the rarest of natural diamond types listed below?
a. Type IIa
b. Type IIb
c. Type IaB
d. Type Ia
e Type Ib
31. What is the estimated current (2026) existing percentage of Type IIa natural diamonds?
a. 0.8%
b. 1.8%
c. 18%
d. None of the above
32. What is more common in Type IIb natural diamonds?
a. Nitrogen
b. Hydrogen
c. Boron
d. None of the above
33. Type Ib natural diamonds are generally colorless.
a. True
b. False
34. What natural diamond type would be more likely in a natural intense fancy yellow?
a. Type Ia
b. Type IaB
c. Type Ib
d. Type IIa
e. None of the above
35. With the presence of nitrogen in Type IaA natural diamond this will most often create a brownish to yellow tint.
a. True
b. False
36. Type IaB most often causes a yellow to brown tint in natural diamond.
a. True
b. False
37. Which of the following help identify a Type IIb diamond.
a. The presence of boron
b. The presence of a blue to grey hue
c. The presence of electrical conductivity
d. All of the above
e. None of the above
38. All blue to grey diamonds are Type IIb.
a. True
b. False
39. Ferromagnetic properties are much more likely to occasionally occur in which of the following?
a. Natural type Ia diamonds
b. CVD diamonds
c. HPHT diamonds
d. None of the above
40. The ferromagnetic properties are due to the presence of the solvent catalyst…
a. nickel.
b. iron.
c. cobalt.
d. are all of the above.
e. are none of the above.
41. When metallic inclusions are identified in a diamond this would indicate which of the following?
a. Type IIb natural diamond
b. A CVD lab-grown diamond
c. An HPHT lab-grown diamond
d. All of the above
e. None of the above
42. Metallic inclusions are common in modern lab-grown diamonds.
a. True
b. False
43. This uncommon dendritic inclusion could occur in...
a. CVD lab-grown diamond
b. HPHT lab-grown diamond
c. None of the above
8.05
44. Approximately what year did the 2.00+ carat CVD grown diamonds dramatically increase in production?
a. 2020
b. 2022
c. 2023
45. It is not important to be knowledgeable in lab-grown diamonds if you are only dealing in natural diamonds?
a. True
b. False
46. Approximately what year did the first 1.00+ carat, near colorless CVD diamond become available?
a. 2008
b. 2009
c. 2010
d. 2011
8.06
1. The Nobel prize winner Henri Moissan discovered natural silicon carbide in a…
a. meteorite.
b. iron ore mine.
c. diamond mine.
2. Natural silicon carbide is common on our planet but difficult to mine.
a. True
b. False
3. Henri Moissan Ph.D was the first to produce moissanite (synthetic silicon carbide).
a. True
b. False
4. Moissanite is identified with a 10x loupe recognizing…
a. polishing lines all going in the same direction.
b. double refraction.
c. its extreme softness.
d. all of the above.
e. none of the above.
f. a. and b.
g. c.
5. Which year did Charles & Colvard introduce synthetic moissanite to the jewelry market?
a. 1988
b. 1998
c. 2001
d. 2008
e. None of the above.
6. When looking through the crown main facet at the culet a moissanite would display…
a. single refraction.
b. double refraction.
c. pleochroism.
d. none of the above.
7. Modern moissanites (2026) are typically tinted yellow, brown or gray.
a. True
b. False
8. Modern moissanites typically have the needle-like inclusion traveling parallel to pavilion.
a. True
b. False
9. It is not possible to use the diamond estimation formula to help determine moissanite identification.
a. True
b. False
10. Diamond’s specific gravity is more or less than moissanite?
a. More
b. Less
c. The Same
11. Natural diamond inclusions do sometimes occur in moissanite.
a. True
b. False
12. The sharpness of the facet edges of moissanite and diamond are the same.
a. True
b. False