If you want to know the difference between diamond cut good vs very good then you can read the article. Whether it’s your engagement ring, necklace or pendant, the diamond you choose will have a huge impact on its appearance. But while color and clarity are incredibly important, your choice of cut can make a bigger difference.
The Gemological Institute of America developed a system for grading cut that takes into account symmetry, proportions and polish. This helps you choose a stone that will sparkle well and hold its value for a long time.
Optical Symmetry
In this article, we find the answer to the question of what does diamond cut mean. Symmetry is the consistency of facet shape, size, and alignment. Misshapen facets, off-center culets and tables, wavy girdles, and irregular crown angles are all a sign of poor symmetry.
When you look at a diamond through an optical symmetry reader, you can see how its facets reflect light in precise three-dimensional patterns. This is what makes the diamond sparkle so brightly and is a key metric to consider when comparing GIA excellent vs. very good cut diamonds.
Optical symmetry is not the same as the meet-point symmetry graded by lab reports. This factor measures how evenly the contiguous facets meet around the stone, which is an indication of craftsmanship.
Unlike meet-point symmetry, optical symmetry is the internal consistency of angle and alignment of a diamond’s facets. It measures the equality of light return and is a more reliable indicator of craftsmanship than the meet-point symmetry grade on lab reports.
Facet Proportions
The size, shape and angle of each facet in a diamond determines its interaction with light. Proportions can range from a very wide variety to extremely narrow, which will affect a diamond’s appearance and sparkle.
When a diamond is properly cut, each facet is angled to maximize the amount of light that can enter and reflect back out of the crown (top) of the diamond. This is what makes a well cut diamond sparkle and shine brightly.
A diamond with good facet proportions will usually have patterns that look like arrows from the top and hearts from the bottom. This is known as the ‘hearts and arrows’ effect.
This property is indicative of a high-end, ideal round cut. However, it does not necessarily mean that the diamond will be the most brilliant or sparkly.
Light Reflection
Light reflection is a key component of diamond quality. It determines the sparkle of a diamond and can make it look larger, whiter or even hide imperfections in its surface.
When light reflects from a smooth surface, it travels in a straight line to the viewer and is seen as a bright ray of light. When light is reflected from a rough surface, it travels in a curved path and can be viewed as a dark ray of light.
GIA classifies diamonds in a range of cut grades, from Excellent to Very Good. The higher the grade, the more fire and brilliance a diamond can demonstrate.
A diamond with an excellent cut has a consistent pattern of bright and dark areas that provide the highest levels of fire and brilliance. They also reflect almost all of the incoming light.
Light Leakage
When a diamond is cut well, light enters the stone and bounces around its facets before it returns to the eye. This results in a sparkle and fire that makes diamonds look bright, sparkly and attractive.
However, a poorly cut diamond will allow light to leak out of the bottom or sides of the stone. This is called “light leakage” and can diminish the diamond’s brilliance, fire, scintillation, and overall beauty.
The AGS Performance Based Cut Grading System evaluates every facet of a diamond (both major and minor) to arrive at a cut grade for each. This approach provides more information about the diamond’s overall light performance than GIA’s proportion based cut grading method which focuses on averages of certain parameters.
The Idealscope and Angular Spectrum Evaluation Tool are the best way to see how a diamond’s facets handle light. These reflector tools show you areas of light leakage and light return, helping you spot diamonds with poor cut quality.
