GIA Certified Diamonds

Mabel & Main offers an official certificate of authenticity from the Gemological Institute of America (GIA), providing tangible and specific verification that the diamond ring is exactly as advertised, giving you peace of mind when making such an important purchase.

While many jewelers provide a bevy of choices for your solitaire stone, our GIA Gemologists select the perfect size and quality stone that balances the final look and price of the ring style you choose. This reduces the headache of chosing center stones and setting separately, while ensuring you're have a GIA Certified Stone in an authentic setting.

  • All solitaire engagement rings are shipped with a corresponding GIA Report number for your center solitaire.
  • If you have a specific GIA Certified stone you wish to set in any of our rings, please reach out to us with the report number and the desired style for a custom quote
  • Cluster engagement rings that are comprised of many smaller (less than 1/5 ct) stones do not come with GIA certificates but will ship with Certificates of authenticity

What is a GIA Certification?

For diamond rings with center stones that are 1/5 carat or greater, you will receive a GIA certification. The Gemological Institute of America is a nonprofit gem research organization. It provides Diamond Grading Reports with thorough and unbiased analysis of a diamond's quality, including color, carat, clarity, and cut. This report is for individual diamonds and not the actual jewelry piece.

GIA Chart Definitions

  1. Shape & Cutting Style - the shape the diamond is cut in (for example, the round brilliant cut is the most common)
  2. Measurements - dimensions in millimeters (mm) of the diamond

  3. Carat Weight - weight in carats, rounded to the nearest 100th of a carat

  4. Color Grade - measuring a diamond for lack of color, based on a D (colorless) to Z (light yellow) scale

  5. Clarity Grade - noting the number, size, relief, nature, and position of internal inclusions and surface blemishes; awarding it a grade on an 11-point scale, from F (flawless) to I (included). Prominent clarity characteristics are noted in reference diagrams.

  6. Cut Grade - evaluating the quality of cut, from excellent to poor, based on 7 different components.

  7. Polish - the overall smoothness, taking into account scratches, nicks, chips, etc.

  8. Symmetry - the outline of the shape, including the shape and placement of facets

  9. Fluorescence - the visible light that a diamond gives off when exposed to ultraviolet (UV) light. The GIA estimates about 25 to 35% of diamonds show some degree of fluorescence – but for the overwhelming majority, this has no noticeable effect on appearance. Fluorescence also has no negative influence on a diamond’s structural integrity.

  10. Proportions - this diagram shows the actual proportions of a diamond, including its depth and table values, as well as its girdle thickness and appearance of facets.

Clarity Characteristics

Natural diamonds form under powerful heat and pressure, and almost all have distinct clarity characteristics. In the GIA report, red symbols mark internal characteristics (inclusions), and green or black symbols mark external characteristics (blemishes).

11. Crystal - a mineral crystal within a diamond.
12. Indented Natural - a natural that dips below a polished diamonds surface.
13. Needle - a long, thin cyrstal that looks like a small rod when magnified
14. Natural - a part of the original surface of the diamond that wasn't removed during the cutting and polishing process.

Browse our GIA Certified Diamond Engagement Rings