GIA Diamond Treatments and Synthetics 3

Question 1

Which of the following treatments is considered permanent and stable under normal wearing conditions?

Accepted Answer

Laser drilling

Answer

Laser drilling creates a permanent tunnel in the diamond and cannot be reversed, unlike fracture filling which can be damaged by heat or chemicals.

Question 2

A HPHT synthetic diamond produced by the flux method is most likely to contain which microscopic feature?

Accepted Answer

Metallic flux inclusions appearing opaque and reflective

Answer

Flux-grown HPHT synthetics frequently contain metallic inclusions (iron-nickel or cobalt) from the flux solvent, which appear opaque and strongly reflective under magnification.

Question 3

When examining a diamond with shortwave UV light, a fracture-filled stone may show:

Accepted Answer

Yellow-green fluorescence in the filled fracture only

Answer

The glass-like filler used in fracture filling often fluoresces yellow-green under shortwave UV, which can help identify treated areas.

Question 4

The term 'diamond simulant' differs from 'synthetic diamond' in that a simulant:

Accepted Answer

Imitates diamond's appearance but has different chemistry

Answer

A simulant (e.g., moissanite, CZ) looks similar to diamond but has different chemical composition, while a synthetic diamond is chemically identical to natural diamond.

Question 5

Which observation under a standard gemological microscope most strongly suggests a diamond has been fracture-filled?

Accepted Answer

Flow lines or trapped gas bubbles within a feather

Answer

Flow lines and trapped gas bubbles visible within a fracture are telltale signs of the glass-like filler injected during fracture filling treatment.

(GIA) Certified Diamonds Gemological Institute of America Practice Test

(GIA) Certified Diamonds Gemological Institute of America Practice Test

GIA Diamond Treatments and Synthetics 3