4 Tips to Avoid Diamonds with Poor Symmetry Grades

4 Tips to Avoid Diamonds with Poor Symmetry Grades


If you’re looking for the perfect diamond, you've probably already learned about the 4 C’s: cut, color, carat, and clarity. Here, we’re going to look a little bit closer at one of these C’s: a diamond’s cut. More specifically, we’ll look at the part a diamond’s symmetry plays when picking out the perfect stone, and how to avoid choosing a diamond with a poor symmetry grade.

1. Understand Diamond Symmetry

If you don’t know what you’re looking for, you won’t be able to avoid it. Put simply, a diamond’s symmetry refers to how well its facets fit together. Extra, misshapen, and poorly aligned facets, wavy girdles, and off-center culets can all affect a diamond’s symmetry.

You can read more in depth about symmetry grade in our post "How to Properly Understand Diamond Symmetry Grade"

If a diamond has a poor symmetry grade its brilliance is reduced. This is because the light is misdirected, and thus will not reflect at ideal angles.

2. Learn About Symmetry Grades

The Gemological Institute of America (GIA) recognizes five symmetry grades:

  • Excellent (E): No symmetry flaws are visible with 10x magnification
  • Very Good (VG): Symmetry flaws are extremely difficult to see with 10x magnification
  • Good (G): Flaws are difficult to see with 10x magnification
  • Fair (F): Flaws are noticeable with 10x magnification, and may be noticeable to the unaided eye
  • Poor (P): Flaws are noticeable to the unaided eye

Most experts recommend buying a diamond with a symmetry grade of Good or higher. Because Excellent and Very Good grade diamonds are rare, diamonds with Good symmetry are sold most frequently. Stones with Poor symmetry should always be avoided.

3. Consider Clarity Grade

The importance of a diamond’s symmetry grade can be affected by its clarity grade. If a diamond is low in clarity, any defects might be less visible. On the other hand, a symmetry grade of Poor or Fair could significantly impact the appearance of a diamond that has a high clarity grade. Symmetry grade is most important when a diamond has a clarity grade of VVS2 or higher.

4. Be Prepared - Check the Keys to Symbol in the Report

If you know what you’re looking for in a diamond, you’re less likely to be disappointed with your final decision. This includes knowing when you should sacrifice a high symmetry grade, and when you should not.

You might think that a poor symmetry grade is the result of an unskilled diamond cutter, but that is rarely the case. Oftentimes, the best cutters will sacrifice symmetry to increase a diamond’s beauty and worth in other ways-- for example, by increasing the carat. As the buyer, it’s your job to decide what characteristics are most important to you, and make your decision accordingly.

Final Tips

  • Avoid Fair and Poor Symmetry Grades.
  • Excellent and Very Good Symmetry Grades are most desirable.
  • Excellent Symmetry Grades can be found at reasonable prices relative to all other grades.
  • Diamonds having superior Symmetry grades should take precedence over Excellent Polish Grades.
  • Always pay particular attention to entries under Keys To Symbols
Frank Fisher

Author: Frank Fisher

Frank Fisher (Sasha Evdakov) started learning about diamonds at a young age through his cultural background and family influence. He spent years being mentored by the best diamond dealers and has been studying diamonds and the diamond market since 1998.