GIA discovers a fake emerald made from quartz assemblage with green cement. Learn about emerald imitations, testing methods, and how gemologists identify synthetic stones.
The green stone turned out to be an elaborate fake.
The Discovery Process
Gemologists at GIA's New York laboratory examined a 7.84-gram stone, which was attached to a necklace.
Initial visual inspection suggested the gem was an emerald.
Testing revealed a different story.
Testing Methods Exposed the Truth
Refractive Index Testing
- Spot measurements indicated quartz properties
- Results contradicted emerald characteristics
Ultraviolet Light Exposure
- Long-wave and short-wave UV revealed whitish fluorescence
- Fluorescence appeared only in internal stone layers
Raman Spectroscopy
- Confirmed material composition as quartz
- Eliminated any doubt about stone identity
Microscopic Analysis Revealed Construction
Detailed examination under the microscope showed:
- Clear separation near the carved top
- Gas bubbles throughout the structure
- Air-filled voids blocking cement flow
- Colorless zones where cement failed to penetrate
The inspection revealed three distinct components:
- Natural rock crystal quartz center
- Green cement layer providing color
- Defined interface between materials
Natural fluid inclusions in the center confirmed authentic quartz origin.
The Soudé Emerald Tradition
Assembled gemstone imitations have fooled buyers for decades.
The soudé emerald represents one of the most common emerald fakes.
Historical Evolution:
- Mass production began in the early 1900s
- Original construction used rock crystal
- Later versions employed colorless synthetic spinel
- Modern fakes use colorless beryl or pale aquamarine
Why This Matters for Gemstone Buyers
This discovery demonstrates the sophistication of modern gemstone fakes.
Professional testing remains the only reliable authentication method.
Visual inspection alone cannot distinguish quality imitations from genuine stones.
Key Takeaways:
- Always request professional gemological certification
- Understand that fake stones can appear convincing
- Know that testing technology continues to advance
- Recognize that imitation techniques also improve
Red Flags to Watch For
Gemstone buyers should be alert to:
- Unusually low prices for "genuine" emeralds
- Sellers are reluctant to provide certification
- Stones with unusual fluorescence patterns
- Visible interfaces or separations in the gem
The GIA's findings, published in the Gems & Gemology quarterly journal, serve as a reminder that gemstone authentication requires expert analysis and proper equipment.
Professional evaluation protects buyers from costly mistakes and ensures confidence in their purchases of precious stones.
The Gemological Institute of America uncovered a sophisticated emerald fake consisting of natural quartz layers bonded with green cement. Advanced testing revealed the deception through refractive index measurements, UV fluorescence, and microscopic analysis. This discovery highlights ongoing challenges in gemstone authentication and the evolution of imitation techniques.
