Lab Certification

Professional gem laboratory certification is available to identify and document the exact characteristics of an emerald. The United States and Switzerland are home to the most renowned and respected independent gemstone laboratories.


  • C. Dunaigre (C.D.)
  • GemTechLab Laboratory (GGTL)
  • Gem Research SwissLab (GRS)
  • Gübelin Gem Lab
  • Swiss Gemological Institute (SSEF)

United States

  • American Gemological Laboratory (AGL)
  • Gemological Institute of America (GIA)

Due to their unique composition, emeralds require special testing equipment – more costly than those for diamonds – in order to properly identify the type, origin, and enhancement level. Enhancement levels are classified as:

  • No Enhancement – extremely rare
  • Insignificant Enhancement – very rare
  • Minor Enhancement – rare
  • Moderate Enhancement – uncommon
  • Significant/Strong Enhancement – common
  • Prominent Enhancement – very common

Because this process is quite expensive, most emeralds that are certified are fine quality and weigh 3 carats and up.