Understanding diamond grading

Posted by Kayla Bray on 17th Nov 2022

Understanding diamond grading

The My Trio Rings Certificate of Authenticity

Every ring comes with a My Trio Rings certificate of authenticity, guaranteeing its gold purity and diamond qualities. This document provides tangible and specific verification that a diamond ring is exactly as advertised, giving you peace of mind when making an important purchase.

GIA Certificate for Higher-Grade Diamonds

For diamond rings with center stones of a higher grade (generally starting at a clarity of SI2, a color of J, and a carat of ⅓), a Gemological Institute of America (GIA) report is also available. This nonprofit gem research organization provides Diamond Grading Reports with thorough and unbiased analysis of a diamond's quality, including the 4 C's and additional grading information. The GIA offers reports only for individual diamonds – not the actual jewelery piece. Here's a breakdown of the most important terms in a GIA report and what they mean:
  1. Shape and Cutting Style The shape the diamond is cut in (for example, the round brilliant cut is the most common)
  2. Measurements Dimensions in millimeters 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 Fluorescence is 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). A few common characteristics are included in this diagram:

  1. Crystal A mineral crystal within a diamond.
  2. Indented Natural A natural that dips below a polished diamond's surface.
  3. Needle A long, thin crystal that looks like a small rod when magnified.
  4. Natural A part of the original surface of the diamond that wasn't removed during the cutting and polishing process.