Provides diamond grading services featuring grading of the diamond cut.

Provides diamond, colored stone and pearls certification, analysis and consultations for the jewelry trade. Produces educational and promotional materials.

Specializes in origin of color determination for fancy colored diamonds using Raman spectrometer. Offers diamond grading reports and appraisal services.

Determination of the authenticity and country of origin of a rubies and sapphires. Offers gemstone reports and inscriptions.

Offers mini and full diamond grading reports and appraisals for the trade. Located in Bellevue, Washington

Independent service provides general information on gemstones, ongoing research and lab report services.

Fine jewelry appraisals by an independent team. Services, price list, and location map. In Manchester, CT.

Technical advisers, appraisers, gemological training. Services, background, and contact information. Located in Brazil.

Offers gemstone analysis software, gemological education, and gemological laboratory services. Includes articles on diamond cut studies and a gallery of virtual diamond images.

An independent, international, non-profit organisation dedicated to the identification, treatment, and origin. Services, education, and contact information. Located in Switzerland.