CGA Gemstone Treatments & Enhancements 3

Question 1

Which instrument is most effective for detecting and identifying oil or resin fillers in emerald fractures in a gemological laboratory?

Accepted Answer

Fourier Transform Infrared Spectroscopy (FTIR)

Answer

FTIR produces an absorption spectrum that acts as a chemical fingerprint, reliably identifying the specific substance used to fill fractures in emeralds, whether natural oils, synthetic resins, or polymers.

Question 2

Under the FTC Jewelry Guides, a jeweler is required to disclose a gemstone treatment when the treatment:

Accepted Answer

Affects the gem's value, durability, or requires special care

Answer

The FTC Jewelry Guides mandate disclosure whenever a treatment affects the gem's value, alters durability, or requires special care from the consumer, regardless of when or where the treatment was applied.

Question 3

An oil-filled emerald requires special care instructions for the buyer primarily because:

Accepted Answer

Ultrasonic cleaners, steamers, and solvents can remove or damage the filler

Answer

Solvents, ultrasonic vibration, and steam can dissolve or dislodge the oil or resin filling, re-exposing the fractures and drastically diminishing the stone's appearance and potentially its appraised value.

Question 4

A CGA appraiser who knowingly fails to disclose a significant gemstone treatment in a written appraisal report is most directly in violation of:

Accepted Answer

USPAP standards and professional ethics requirements

Answer

USPAP (Uniform Standards of Professional Appraisal Practice) requires appraisers to report all known factors that materially affect value; omitting a treatment disclosure violates USPAP ethics rules and the ASA/AGS codes of professional conduct.

Question 5

GIA's emerald clarity enhancement grading uses which terminology to describe the degree of fracture filling?

Accepted Answer

None, Minor, Moderate, Significant

Answer

GIA uses a four-tier scale — None, Minor, Moderate, and Significant — to describe the degree to which an emerald's fractures have been filled, which directly impacts the gem's market value.

(CGA) Certified Gemologist Appraiser Practice Test

(CGA) Certified Gemologist Appraiser Practice Test

CGA Gemstone Treatments & Enhancements 3