The cut of a diamond has the most effect on its sparkle, or brilliance. Even with perfect color and clarity, a poor cut can make a diamond look dull. Learn how to choose the right diamond cut with the most brilliance for your budget.
The cut of a diamond determines its brilliance. There is no single measurement of a diamond that defines its cut, but rather a collection of measurements and observations that determine the relationship between a diamond’s light performance, dimensions and finish. Most gemologists consider cut the most important diamond characteristic because even if a diamond has perfect color and clarity, a diamond with a poor cut will have dulled brilliance.
How a Diamond is Cut
|Determining a diamond’s cut grade, however, goes beyond simple measurements of width and depth. Using an optical measuring device, a three-dimensional model is created to determine the diamond’s proportions and angles. The interrelations between these various dimensions will greatly affect how light reacts once it enters and how it behaves once it exits; by using sophisticated computer modeling, it is possible to trace light behavior and measure its levels of brightness, fire and scintillation – the face-up appearance.
Diameter: The width of the diamond as measured through the girdle.
Table: The largest facet of a gemstone.
Crown: The top portion of a diamond extending from the girdle to the table.
Pavilion: The bottom portion of a diamond, extending from the girdle to the culet.
Culet: The facet at the tip of a gemstone. The preferred culet is not visible with the unaided eye (graded “none” or “small”).
Girdle: The intersection of the crown and pavilion which defines the perimeter of the diamond.
Depth: The height of a gemstone measured from the culet to the table.
The width and depth can have an effect on how light travels within the diamond, and how it exits in the form of brilliance.
Too Shallow: Light is lost out the bottom causing the diamond to lose brilliance.
Too Deep: Light escapes out the sides causing the diamond to appear dark and dull.
Polish and Symmetry
Polish and symmetry are two important aspects of the cutting process. The polish grade describes the smoothness of the diamond’s facets, and the symmetry grade refers to alignment of the facets. With poor polish, the surface of a facet can be dulled, and may create blurred or dulled sparkle. With poor symmetry, light can be misdirected as it enters and exits the diamond. The polish and symmetry grades are clearly listed in each diamond detail page and within the GIA or AGSL diamond grading report. For the most beautiful diamond, look for a symmetry grade of excellent (EX), very good (VG), or good (G) for a GIA graded diamond, and ideal (ID), excellent (EX), very good (VG), or good (G) for an AGSL graded diamond. Avoid diamonds with symmetry grades of fair (F) or poor (P), as the alignment of their facets may misdirect light so severely that it affects the brilliance of the diamond.
Diamond Cut Grading
Diamond measurements are calculated and applied to a cut grading scale that makes it easy to understand how well each reflect light:
- Ideal cut: Represents roughly the top 3% of diamond quality based on cut. Reflects nearly all light that enters the diamond. An exquisite and rare cut.
- Very good cut: Represents roughly the top 15% of diamond quality based on cut. Reflects nearly as much light as the ideal cut, but for a lower price.
- Good cut: Represents roughly the top 25% of diamond quality based on cut. Reflects most light that enters. Much less expensive than a very good cut.
- Fair cut: Represents roughly the top 35% of diamond quality based on cut. Still a quality diamond, but a fair cut will not be as brilliant as a good cut.
- Poor cut: This includes all diamonds that do not meet the performance standards of a fair cut. These diamonds are generally deep and narrow or shallow and wide and tend to lose most of the light out the sides and bottom.
Acting as a prism, a diamond can divide light into a spectrum of colors and reflect this light as colorful flashes called fire. Just as when looking through colored glass, color in a diamond will act as a filter, and will diminish the spectrum of color emitted. The less color in a diamond, the more colorful the fire, and the better the color grade.
Fluorescence and Diamonds
Some people seek diamonds that produce this unique effect, while others definitely avoid it. The visible effects of fluorescence grades of faint, inert, negligible, and medium, can only be detected by a trained gemologist. A fluorescence grade of strong or very strong can make a diamond with a near-colorless grade look even whiter yet in some instances give the diamond a slight hazy or oily appearance. Diamonds with a strong or very strong fluorescence are priced slightly lower than other diamonds.
What Color Grade Is Best?
- For the purist, look for a colorless diamond with a grade of D-F and a fluorescence rating of faint, inert, none, or negligible.
- For an excellent value in a diamond with no noticeable color to the unaided eye, look for a near-colorless grade of G-I, and a fluorescence grade of medium or strong blue.
- Or, if you’d rather not compromise on color but would like to stay on budget, choose a diamond with a good cut, SI1–SI2 clarity, and consider going with a strong fluorescence. It will still be beautiful to the unaided eye and you may prefer the unique effect of a strong fluorescence.
Diamonds that are absolutely clear are the most sought-after and therefore the most expensive. But many diamonds have inclusions — scratches, trace minerals or other tiny characteristics that can detract from the pure beauty of the diamond. The GIA and AGSL use a detailed system of rules and standards to summarize the number, location, size, and type of inclusions present in a diamond.
FL, IF Diamonds: Flawless: No internal or external flaws. Internally Flawless: No internal flaws. Very rare and beautiful diamonds.
VVS1, VVS2 Diamonds: Very, Very Slightly Included: Very difficult to see inclusions under 10x magnification. An excellent quality diamond.
VS1, VS2 Diamonds: Very Slightly Included: Inclusions are not typically visible to the unaided eye. Less expensive than the VVS1 or VVS2 grades.
SI1, SI2 Diamonds: Slightly Included: Inclusions are visible under 10x magnification, and may be visible with the unaided eye (SI2).
I1, I2, I3 Diamonds: Included: Inclusions are visible to the unaided eye.
What Clarity Grade Is Best?
We recommend that you select an “eye-clean” diamond — one that has no inclusions visible to the unaided eye. An excellent value, diamonds of this clarity are much less expensive than IF- or FL-grade diamonds and typically do not contain visible inclusions that detract from the beauty of the diamond. If you’re considering an SI grade diamond, call to speak to a diamond and jewelry consultant who will review the diamond to ensure the inclusions are not visible with the unaided eye. But, if you’d rather not compromise on clarity yet are budget conscious, choose a diamond with a good cut and G or H color.
Once you’ve determined what cut, color, and clarity grade you’re looking for in a diamond, it’s easy to determine the carat weight of diamond that will fit within your budget.
What Size Is Best?
To choose the best carat weight of a diamond, consider her style, the size of her finger, the size of your setting, and your budget.
- If you have a set budget, explore all your options and you’ll find that there is a wide range of diamond carat weights and qualities available in your price range.
- If your recipient is very active or not used to wearing jewelry, she may find herself bumping or nicking her new ring. Consider a smaller size diamond or a setting that protects a larger diamond from getting knocked against doors and counters.
- Also keep in mind that the smaller the finger, the larger the diamond will appear. A 1½-carat diamond solitaire looks much larger on a size 4 finger than a size 8.
- If you have already chosen a setting, make sure you choose a diamond to fit. Look for the diamond size specifications of your ring or ask your Shannon Fine Jewelry sales associate what size diamond you should look for.
- Finally, if a large carat weight is important to you, yet you’re working within a budget, consider a diamond with a good cut, SI1–SI2 clarity, and an I or J color grade.
What is a Certificate?
A diamond certificate, also called a diamond grading report, diamond dossier®, or diamond quality document, is a report created by a team of gemologists. The diamond is evaluated, measured, and scrutinized using trained eyes, a jeweler’s loupe, a microscope, and other industry tools. A completed certificate includes an analysis of the diamond’s dimensions, clarity, color, polish, symmetry, and other characteristics. Many round diamonds will also include a cut grade on the report.
Shannon Fine Jewelry sells diamonds that have been analyzed and graded by either the European Gemological Laboratory (EGL) or the Gemological Institute of America (GIA). These two laboratories are among the most respected laboratories in the diamond industry, and are known for their consistency and unbiased diamond grading systems. Diamonds that are accompanied by these grading reports are highly valued in the industry.
Diamonds are the hardest substance on earth. They are uniquely resistant to damage by heat or scratching, and can be cut or polished only by another diamond — but an extremely hard blow to the girdle can cause a diamond to chip. By having your diamond set in a relatively protective setting, and remaining conscious of it on your finger, you can keep your diamond intact for a lifetime. Exposure during ordinary wear to perspiration and household chemicals, like chlorine and hairspray, can cause buildup that dulls the surface of a diamond. We suggest periodic cleanings to keep the diamond brilliant and refractive.
Cleaning Your Diamonds
A solution of one part ammonia, three parts liquid dish soap and six parts water can be used to clean diamond jewelry at home. If cleaning by hand, gentle scrubbing with a soft brush should loosen most dirt and greatly increase the brilliance of the diamond, but be careful not to scratch the metal of your setting. Once a year, it is a good idea to have your diamond cleaned and have the security of the setting checked.
Storing Your Diamond Jewelry
We recommend that all diamond jewelry is stored individually in soft cloth pouches when not being worn to prevent the diamond or diamonds from scratching or dulling other jewelry.