September 23, 2020
One of the 4Cs, a diamond's cut refers to how well it is proportioned and polished to maximize brilliance and fire. Cut is considered the most important C since it has the greatest influence on a diamond's sparkle and beauty. This guide will cover everything you need to know about diamond cut, from grading criteria to how it impacts value.
A diamond's cut grade does not refer to its shape (round, oval, etc). Rather, it is an evaluation of how well the diamond is cut proportionally to optimize light performance.
Precise cutting and polishing are required to achieve ideal proportions and symmetry. This allows light to reflect and refract optimally off a diamond's precisely angled facets. When cut to ideal parameters, a diamond will have exceptional brilliance (white light reflection) and fire (spectral color dispersion).
The quality of the cut is a major factor that determines how beautifully a diamond interacts with light. A top-tier cut grade can make an average diamond look exquisite, while a poor cut can make even a large diamond appear dull.
GIA (Gemological Institute of America) uses a cut grading system with 5 main categories, from best to worst:
While Excellent and Very Good represent well-cut diamonds, Good and Fair grades mean the diamond is cut too deep, shallow, or off-proportion. This reduces light return through the crown.
A Poor cut grade is significantly outside standard parameters. It causes major light leakage out the sides and bottom. A Poor cut should always be avoided as it negates the natural beauty of diamond.
Several factors are analyzed to determine a diamond's cut grade:
When a diamond is cut with excellent proportions, symmetry, and polish, the result is maximum brilliance and fire. Each factor is analyzed during grading.
The parts of a diamond are designed to optimize interaction with light. Here are the key anatomical elements:
The proportions, alignment, and polish of the crown, pavilion, table, and other facets are all considered when analyzing diamond cut quality.
Diamond cut and diamond shape are related but distinct terms. Shape refers to the diamond's outline form - round, oval, pear, etc. It is unrelated to cut grade. A round brilliant can be Poorly cut or Excellently cut.
Cut is an appraisal of how well a diamond is fashioned - its proportions, symmetry, and polish. It determines light performance, brilliance, and fire. So two diamonds of the same carat weight and shape can have vastly different cut grades and visual appeal.
Along with carat weight, clarity, and color, cut quality is a primary driver of diamond prices. Diamonds with Excellent or Very Good cut grades command significant premiums over those with lower cut grades.
For example, a 1 carat round H-VS2 diamond may sell for:
That's nearly a $3,000 difference between an Excellent and Poor cut of the same shape, carat weight, clarity and color!
Cut is so important because it has the greatest influence on a diamond's appearance and ability to scintillate brilliantly. Even if two diamonds share identical 4Cs, the one with superior cut will appear far more dazzling and fiery to the eye.
Diamond cutting expertise has improved enormously over the decades. Today, even budget-friendly diamonds can achieve high cut grades. With some education and diligence, finding a stunning well-cut diamond is within reach for every buyer.
Understanding diamond cut is key to selecting a stone that dazzles with optimal brilliance and fire. If you invest in an Excellent or Very Good cut, even an average diamond can look exquisite under the light. Let us know if you have any other questions about diamond cut in the comments!
Comments will be approved before showing up.