CGC Gemstone Treatments & Enhancements Flashcards
6 cards from real CGC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CGC Gemstone Treatments & Enhancements flashcards as text
What is the industry-accepted scale used by GIA to describe the degree of clarity enhancement in emeralds?
Answer: None, Slight, Moderate, Significant, Prominent
GIA uses 'None, Slight, Moderate, Significant, Prominent' to describe the degree of clarity enhancement in emeralds, reflecting the industry norm of filler-degree grading.
Which gemstone is commonly subjected to surface diffusion treatment to produce a star or color effect?
Answer: Corundum (ruby/sapphire)
Corundum (rubies and sapphires) can be treated with surface diffusion to create or enhance star effects (asterism) or to produce color confined to the surface layer.
What does 'flux healing' refer to in the context of ruby treatment?
Answer: A heat treatment using flux material to heal surface fractures in rubies
Flux healing involves heating rubies in flux material (such as borax) to partially heal or fill surface-reaching fractures, improving apparent clarity.
Why is UV fluorescence testing useful when identifying treated diamonds?
Answer: Treatments and fracture fillings often produce distinctive or unusual fluorescence patterns
Fracture fillings, HPHT treatments, and other enhancements often produce distinctive fluorescence patterns under UV light that differ from untreated diamonds, aiding detection.
What is the primary reason the FTC mandates treatment disclosure in the U.S. gemstone market?
Answer: To protect consumers from material misrepresentation that affects value and care requirements
FTC mandates treatment disclosure to protect consumers from purchasing treated stones they believe are natural, as treatments materially affect both value and required care.
Which laboratory technique uses infrared spectroscopy to detect filler substances in emerald fractures?
Answer: FTIR (Fourier Transform Infrared) spectroscopy
FTIR spectroscopy identifies the molecular signature of filler substances (oils, resins, polymers) in emerald fractures, helping gemologists determine the type and extent of treatment.
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