What is Diamond Symmetry and How is it Grade? (Round Cut Diamonds)

Diamond symmetry refers to how precisely the various facets of a diamond align and intersect. This can include factors such as how the edges align, whether the facets are uniform in shape and size, and how the facets meet at points and corners. Essentially, it is an indication of a diamond cutter’s ability to produce a well-proportioned diamond. A high level of symmetry is essential to maximizing a diamond’s brilliance, fire, and overall visual appeal.

When choosing a diamond, look for grading reports that offer symmetry ratings. These are usually ranked on a scale from ‘Poor’ to ‘Excellent’ by major diamond laboratories such as the GIA. If you are aiming for a diamond that offers the most brilliance and fire, it is recommended that you look for a ‘Very Good’ or ‘Excellent’ symmetry rating. In terms of price, diamonds with higher symmetry ratings are generally more expensive as they require a higher level of craftsmanship. This cost can be justified by the superior light performance and overall appearance of the stone. Therefore, it is worth investing in a diamond with good symmetry to ensure that you are getting a stone that will truly shine.

Diamond Symmetry Chart

How does symmetry affect a Diamond?

Symmetry affects how well a diamond interacts with light and how brilliant a diamond is. A diamond with good symmetry allows light to pass through the diamond as it should. Light bounces off surfaces and angles and bounces back through the table to your eyes.

A diamond with poor symmetry sends light at imperfect angles, meaning light can exit from the bottom or sides of the diamond. When light is not reflected into the eye, the diamond appears dull. Therefore, symmetry is critical to the beauty of a diamond. .

How is Symmetry in Diamonds Grade?

The GIA measures symmetry levels as Excellent, Very Good, Good, Fair, and Poor. According to the GIA , a diamond's The degree of symmetry is based on visibility at 10x magnification (a standard jeweler's loupe) and the presence of aberrations. Several aspects come into play when grading a diamond for symmetry, including misalignment, missing facets, variation in the thickness of the diamond's girdle, extra facets and an off-center table.

Here is a breakdown of degrees of symmetry:

Perfect: Perfectly symmetrical diamonds have very little aberration, their tables are centered, and they have no extra or missing facets.

Very good: Diamonds with Very Good symmetry have a few slight deviations. There may be a slight misalignment or a misshapen surface.

Good morning my baby: Diamonds with good symmetry have few aberrations. The brilliance of a diamond can be affected by aspects such as a change in angle or a missing facet.

Fair: Diamonds with fair symmetry have a variety of aberrations. The brilliance of a diamond is diminished by misalignments, variations, and misshapen features.

Bad: Diamonds graded with poor symmetry have many obvious aberrations. The diamond is likely to appear dull. There may be a combination of an off-center table, missing facets, variations, and misshapen surfaces.

Is Diamond Symmetry More Important Than Polish?

The simple answer to this question is: Not really.

Each of the problems mentioned here (off-centered crown, off-centered table, misshapen surfaces, out-of-round perimeter, crown misalignment, and wavy girdle) can certainly detract from the beauty and appeal of a diamond.

Telling the Difference Between Diamond Symmetries

As diamond experts with many years of experience, we recommend that you consider the cut and cut quality at the highest levels in your diamond preferences, if you want a shining stone. If you want the ''most'' shining stones, do not forget that there are high qualities beyond these ratings and do not hesitate to consult our knowledge and experience.