While often overlooked, diamond symmetry plays a critical role in how a diamond reflects light — and ultimately, how much it sparkles.
At Tang&Co., we believe every detail matters. Symmetry isn’t just a technical term; it’s part of what transforms a diamond from beautiful to breathtaking.
Let’s take a closer look at what symmetry means, why it affects brilliance, and how to choose a diamond with ideal proportions.
What Is Diamond Symmetry?
In gemology, symmetry refers to the precise alignment and balance of a diamond’s facets, not whether the diamond is a perfect mirror image from side to side.
A well-symmetrical diamond has:
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Evenly shaped and placed facets
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A centered table and culet
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Proper alignment between the crown, pavilion, and girdle
The better the symmetry, the more light performance, balance, and overall beauty the diamond delivers.
Why Is Symmetry Important?
Symmetry directly impacts a diamond’s ability to reflect and refract light — the key to that irresistible sparkle.
Diamonds with excellent symmetry maximize brilliance and fire, while poorly symmetrical stones may leak light and appear dull.
While not one of the “4Cs,” symmetry is deeply connected to cut grade.
Diamonds graded Excellent or Very Good in cut typically have strong symmetry and superior sparkle.
What Causes Poor Symmetry?
Several technical flaws can lead to symmetry issues, including:
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Misaligned or uneven facets
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An off-center table or culet
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A table that isn’t parallel to the girdle
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Crown and pavilion do not in angle or alignment
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Extra or missing facets
These inconsistencies may go unnoticed to the untrained eye, but under magnification, they can dramatically affect performance and value.
How to Know if a Diamond Has Good Symmetry
The easiest way? Check the cut grade.
Cut is graded from Excellent to Poor, and it reflects how well the diamond’s proportions, polish, and symmetry work together.
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Excellent: Ideal symmetry, perfectly proportioned facets, and maximum sparkle
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Very Good: Minor deviations, often invisible to the naked eye
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Fair/Poor: Noticeable misalignment, reduced brilliance, and uneven facet structure
At Tang & Co., we only curate center stones with Excellent or Very Good symmetry — ensuring your diamond is as visually stunning as it is well-crafted.
Does Symmetry Affect Price?
Yes — symmetry plays a role in diamond pricing.
Diamonds with Excellent symmetry typically command a premium, especially in round brilliant cuts, where perfection is easier to spot.
However, Very Good symmetry can offer exceptional value, especially if the diamond appears eye-perfect to you.
Fancy shapes (like ovals, pears, and cushions) may show more tolerance in symmetry grading without sacrificing beauty.
Conclusion: Symmetry That Shines
While symmetry might seem like a subtle technical detail, it has a major impact on how your diamond performs in real life.
The more symmetrical your diamond, the more dazzling it will appear — now, and for decades to come.
At Tang&Co, we’re committed to helping you find a diamond that’s not just beautiful, but masterfully crafted in every detail.