The GIA, short for Gemological Institute of America, is the most highly regarded institution of the assessment and certification of diamonds.

Diamond certificates issued by the GIA are like a diamond ID: They capture all of the diamond’s unique characteristics. Most importantly, they provide clarification about the diamond’s quality.

The main points covered by the reports are the 4C, a set of criteria that was established by the GIA for the assessment of diamonds.

The 4Cs – color, clarity, cut, carat weight – where established by the GIA in the 1940s. Read more on the 4Cs and how to find your personal trade-off between them here.

A GIA certificate includes all the information you need to know about your diamond:

1. Date of examination
2. Report Number
3. Shape and Cutting Style
4. Measurements (Not to be mistaken for carat weight!)
5. Carat weight
6. Color grade
7. Clarity grade
8. Cut grade (While shape and cutting style describes the actual appearance a diamond, the cut grade assesses the quality of the cut in more detail, like the arrangement of the facets. The scale ranges from Excellent to Poor.)
9. Polish (Smoothness of the diamond’s surface)
10. Symmetry (measures how symmetrical the shape, placement, and alignment of the facets are)
11. Fluorescence (Assessed under long-wave ultraviolet light and examines how fluorescent a diamond is. 33% of all natural diamonds exhibit fluorescence to a certain degree)
12. Inscriptions (Texts, symbols, logos, GIA report number inscribed on the diamond’s girdle)
13. Comments (e.g. detection of a treatment)
14. Proportion diagram
15. Plotted diagram
16. Key to symbols
17. GIA Color Scale
18. GIA Clarity Scale
19. GIA Cut Scale
20. Security Features (for document authentication)
21. QR-Code (for verification of the report against the GIA database)

• The Gemological Institute of America (GIA)
• The 4C
• Finding your personal trade-off between the 4C