This content was first published on IGR – Italian Gemological Review no. 20 in 2025. The information provided here is therefore current as of the original publication date.
As of December 15, 2024, GIA has been providing optional filler identification in its emerald reports, initially free of charge. In response to market demand, the service specifies the type of filler used, classifying fillers as Type A (oil, wax, or natural resin), Type B (artificial resin), or indicating if the filler cannot be identified. This enhancement complements GIA’s assessment of emeralds’ identity and filler degree, addressing industry concerns about filler composition.
As highlighted in issue 10 of IGR, dedicated to emerald filling, filler identification relies on advanced spectroscopic methods such as FTIR (Fourier Transform Infrared Spectroscopy) or Raman spectroscopy, which distinguish materials based on their chemical properties. However, it is primarily the quantitative analysis that significantly impacts emerald evaluation. This involves visual inspection combined with spectroscopic techniques to estimate the extent of filling. Most renowned laboratories classify the extent of filling into levels:
- Minor: Minimal filling of fissures, resulting in subtle treatment.
- Moderate: More evident filling, though not excessive.
- Significant: Extensive filling of fissures, greatly enhancing the emerald’s clarity.
Gem News published on IGR – Italian Gemological Review #20 – Winter 2024/25
