DCA Diamond Treatments & Enhancements 2

Question 1

Which of the following diamond colors can be produced through irradiation treatment?

Accepted Answer

A wide range including blue, green, yellow, and pink

Answer

Only colorless (D-F range)

Answer

Only brown shades

Answer

Only black diamonds

Question 2

Under magnification, how can a gemologist detect laser drilling in a diamond?

Accepted Answer

By finding a thin white tunnel or channel leading to a dark inclusion

Answer

By observing a flash of color along the drill path

Answer

By detecting a hardness reduction in the drilled area

Answer

By identifying a refractive index mismatch at the surface

Question 3

Which characteristic of a fracture-filled diamond may change over time or with exposure to chemicals?

Accepted Answer

The apparent clarity improvement from the filler

Answer

Its carat weight

Answer

Its surface hardness

Answer

Its refractive index reading

Question 4

The Yehuda process is a well-known proprietary method for which type of diamond treatment?

Accepted Answer

Fracture filling

Answer

HPHT color enhancement

Answer

Laser drilling

Answer

Surface coating

Question 5

Which type of diamond treatment is generally considered permanent and does NOT require ongoing disclosure concerns about stability?

Accepted Answer

Laser drilling

Answer

Fracture filling

Answer

Surface coating

Answer

Polymer impregnation

Question 6

How does surface coating on a diamond typically appear when examined under a loupe or microscope?

Accepted Answer

It may show as a thin film, abrasions, or color concentration at facet junctions

Answer

It appears as a deep internal haze

Answer

It creates a distinctive star pattern at the culet

Answer

It causes a double refraction visible through the table

Question 7

If a diamond has been irradiated and then annealed, what is the likely reason for the annealing step?

Accepted Answer

To stabilize and modify the color produced by irradiation

Answer

To increase the diamond's hardness rating

Answer

To remove the laser drill channels created during treatment

Answer

To fill internal fractures with a glass-like substance