Gemology Certification Gem Treatments & Enhancements 2

Question 1

Which gemological instrument is most effective for detecting fracture-filling treatments in gemstones?

Accepted Answer

Microscope

Answer

Refractometer

Answer

Spectroscope

Answer

Chelsea filter

Question 2

The 'flash effect'—an iridescent blue or orange flash visible under magnification—is most diagnostic of which treatment?

Accepted Answer

Fracture filling

Answer

Heat treatment

Answer

Irradiation

Answer

Diffusion treatment

Question 3

Which of the following gemstones is NOT typically subjected to heat treatment as a standard trade practice?

Accepted Answer

Emerald

Answer

Ruby

Answer

Blue sapphire

Answer

Tanzanite

Question 4

A diamond described as 'laser drilled' has undergone a treatment intended to improve which property?

Accepted Answer

Clarity

Answer

Color

Answer

Cut symmetry

Answer

Fluorescence

Question 5

Under GIA's grading system for colored stones, which disclosure term indicates no evidence of clarity or color treatment was found?

Accepted Answer

None detected

Answer

Minor

Answer

Natural

Answer

Not applicable

Question 6

What diagnostic feature under the microscope helps gemologists identify heat-treated rubies compared to non-treated ones?

Accepted Answer

Melted, broken, or absent silk (rutile needles)

Answer

Intact, unbroken silk (rutile needles) in their original orientation

Answer

Increased number of fingerprint inclusions

Answer

Presence of flux inclusions

Question 7

Lead glass filling is most strongly associated with improving the appearance of which gemstone?

Accepted Answer

Ruby

Answer

Sapphire

Answer

Emerald

Answer

Tanzanite