AGTA, The AGTA Gemological Testing Center (AGTA GTC) is the natural colored gemstone industry's premier independent laboratory. The AGTA GTC serves the industry and the public with a complete range of services, including gemstone identification, origin determination and pearl identification. The laboratory is equipped with the latest, technologically advanced, investigative equipment. Many of our top gem quality gemstones are accompanied by a gem identification report from the American Gem Trade Association (AGTA).