IGI Summation


IGI Summation


International Gemological Institute (IGI) provides you with 40+ years of gemstone grading experience. The current staff is comprised of over 600+ gemologist appraisers and professionals support staff. Purchasing an IGI certified gemstone provides a level of confidence to both the seller and buyer. Certificate from IGI empowers jewelry buyers to focus on finding exactly what they want, with full guarantee in the honesty and excellence of the IGI certification.

Established in Antwerp, Belgium, IGI has been in the business of certifying gemstones since 1975.

Glossary of Summation Terms

  • Date: The IGI summation completion date.
  • Identification: The gemstone family or species.
  • Shape/Cutting Style: Describes the visual shape the gemstone produced after cutting.
  • Carat Weight: The actual weight of the gemstone.
  • Measurements: Length X Width X Depth for round stones Diameter X Depth. All measurements are in millimeters
  • Color: As close to capturing the color range of the stone.
  • Clarity: A grading for internal characteristics and blemishes.
  • Cut Quality: Takes into account the symmetry of the cut and smooth surfaces of the facets.
  • Origin: This is the gemstone source location.
  • Laser Scribed: The summation number will be lasered into your gemstone. However, you will need a magnifying glass to see the summation number.