DCA Diamond Treatments & Enhancements

Question 1

What does the abbreviation HPHT stand for in the context of diamond treatment?

Accepted Answer

High Pressure High Temperature

Answer

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?

Accepted Answer

Laser drilling

Answer

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?

Accepted Answer

Glass-like substance with similar refractive index

Answer

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?

Accepted Answer

The report notes 'laser drill hole' as a clarity characteristic

Answer

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?

Accepted Answer

Brown or near-colorless diamonds with nitrogen defects

Answer

HPHT treatment is frequently applied to brownish diamonds, rearranging their crystal structure to produce colorless or near-colorless stones.

(DCA) Certified Diamond Council of America Diamond Specialist Practice Test