Gemstone Treatments & Enhancements Flashcards

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

Answer: Fourier Transform Infrared Spectroscopy (FTIR)

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.

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

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

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.

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

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

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.

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

Answer: USPAP standards and professional ethics requirements

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.

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

Answer: None, Minor, Moderate, Significant

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.

When appraising a ruby described as 'no heat' by the seller, a CGA appraiser should:

Answer: Recommend laboratory testing and use qualified language pending verification

A CGA must practice due diligence; without an independent laboratory report from a reputable lab (GIA, Gübelin, SSEF), the appraiser should state 'reportedly no heat treatment' and recommend testing, as no-heat rubies command significant price premiums.

Which of the following statements about HPHT diamond treatment is accurate for appraisal purposes?

Answer: HPHT is a permanent treatment that significantly affects market value and must be disclosed

HPHT treatment is permanent and cannot be reversed, but it is a treatment applied to natural diamonds that substantially affects market perception and value; full disclosure is required by the FTC and professional appraisal standards.