DCA Diamond Treatments & Enhancements 1 — Questions and Answers
Question 1: What does the abbreviation HPHT stand for in the context of diamond treatment?
- High Pressure High Temperature (Correct answer)
- High Polish Heat Treatment
- Hydrothermal Process Heat Transfer
- Hardness Purity Hue Testing
Correct answer: High Pressure High Temperature
HPHT stands for High Pressure High Temperature, a process that subjects diamonds to extreme conditions to alter their color.
Question 2: Which diamond treatment is specifically used to remove or reduce the visibility of dark inclusions?
- Fracture filling
- Laser drilling (Correct answer)
- HPHT treatment
- Surface coating
Correct answer: Laser drilling
Laser drilling uses a laser beam to vaporize or bleach dark carbon inclusions, creating a channel that can be further treated with acid.
Question 3: What material is most commonly injected into a diamond during fracture filling?
- Epoxy resin
- Glass-like substance with similar refractive index (Correct answer)
- Liquid nitrogen
- Silicone sealant
Correct answer: Glass-like substance with similar refractive index
Fracture filling uses a glass-like substance whose refractive index closely matches that of diamond, making cracks less visible.
Question 4: How does laser drilling typically affect a diamond's clarity grade on a GIA grading report?
- It is not disclosed and has no effect on the grade
- The report notes 'laser drill hole' as a clarity characteristic (Correct answer)
- The diamond is automatically downgraded two grades
- The report lists it as a natural inclusion
Correct answer: The report notes 'laser drill hole' as a clarity characteristic
GIA reports identify laser drill holes as a clarity characteristic, noting the treatment while still grading the stone's apparent clarity.
Question 5: HPHT treatment is most commonly used on which category of diamonds to improve their appearance?
- Fancy colored yellow diamonds
- Brown or near-colorless diamonds with nitrogen defects (Correct answer)
- Included diamonds with visible fractures
- Heavily fluorescent blue diamonds
Correct answer: Brown or near-colorless diamonds with nitrogen defects
HPHT treatment is frequently applied to brownish diamonds, rearranging their crystal structure to produce colorless or near-colorless stones.
Question 6: Which industry body requires mandatory disclosure of all diamond treatments to consumers?
- The Federal Reserve
- The Federal Trade Commission (FTC) (Correct answer)
- The American Gem Society (AGS) only
- The Diamond Producers Association
Correct answer: The Federal Trade Commission (FTC)
The FTC requires full disclosure of all treatments that alter a diamond's appearance, including fracture filling, laser drilling, and HPHT.
Question 7: What is the primary concern with fracture-filled diamonds when a customer brings jewelry in for repair?
- The filler makes the diamond more brittle and prone to chipping
- High heat from torch work can damage or destroy the filler material (Correct answer)
- The filler causes the diamond to lose weight over time
- Ultrasonic cleaners permanently bond the filler to the host diamond
Correct answer: High heat from torch work can damage or destroy the filler material
The glass-like filler in fracture-filled diamonds has a much lower melting point than diamond, so jeweler's torch heat can melt, discolor, or remove it.
DCA Diamond Treatments & Enhancements 1
What does the abbreviation HPHT stand for in the context of diamond treatment?