The Cut Scale
Fair & Poor: Diamonds with significant light leakage earn a Fair or Poor grade. These diamonds tend to leak noticeable amounts of light from being too deep or shallow in height. These have little brilliance and are less visually appealing. Fair or Poor cut diamonds do not meet Four Mine’s minimum light performance criteria. This cut category represents the top 35% of gem quality diamonds. Avoid these diamonds as they will not make for sparkling jewelry.
Very Good: Very well cut diamonds that capture almost all the potential of the diamond. Very brilliant with minimal light leakage. Diamonds cut often intentional cut to achieve a Very Good grade so that can improve the other characteristics of the diamond such as Color, Clarity or Carat. The top 15% of gemstone quality diamonds are Very Good cut. Very Good cut diamonds can be a great choice if looking mazimize value on the other factors.
Good: Well cut diamonds that capture light and possess high degrees of sparkle. Good cut diamonds have some light leakage, but overall shine bright. These diamonds can have noticeably larger or even smaller measurements than perfectly cut diamonds of the same shape. Cutters may intentionally cut to Good proportions to achieve a particular look or style. The top 25% of diamonds have a Good cut grade. Good cut diamonds can be a good blend of value and size, however be careful and always ask a gemologist to assess the particular diamond for you before you make a decision.
Excellent: The highest grade representing the top diamonds in the world. Diamonds with an Excellent cut grade are masterfully crafted and precisely cut to unleash the maximum sparkle and brilliance of a diamond. Little or no light leakage occurs as light passes through a diamond. This premium category represents the top 3% of all diamonds. Excellent cut diamonds are increasing with improvements in manufacturing technology. An excellent cut diamond is always a good choice regardless of diamond shape and size.
Finish: Polish, Symmetry and Facets
Step cuts, such as Emerald cut diamonds and Asscher cut diamonds, have sparkle or fire. They have facets that look like a staircase and are a bit simpler in presentation. They are considered very elegant and maximize the diamond’s scintillation. These cuts are elegant but because they have fewer facets do not reflect light as much as brilliant cut diamonds. While both diamonds have unique beauty, it is important to consider which type of diamond sparkle you want while picking a diamond cut.
Brilliant cuts, most commonly Round cut diamonds or Princess cut diamonds, have maximum diamond sparkle. They possess more facets than step cuts and the facets are triangular and kite-shaped. Brilliant cuts have a high degree of diamond sparkle and maximum the fire and scintillation of a diamond.
The other two attributes of finish are polish and symmetry. Both of these are a result of the manufacturing process. The polish of a diamond is how cleanly smooth the facet surfaces are. If small striated polish lines remain, it may affect light performance and therefore, diamond cut. The other attribute is symmetry. Symmetry is simply the pattern and evenness of the size, shape and location of facets. If the location of a facet is incorrect, the performance of light and therefore the cut grade can be affected. For example, an off center table facet may reduce diamond sparkle.
Selecting Cut Grade
Cut is often consider the most important of the 4 C’s of diamonds (carat is more of a preference, not an art or science). When selecting a diamond, it will certainly important to ensure light is not lost. Excellent cuts are most premium and Very Good cuts offer more value. The differences in sparkle are quite subtle, but they are noticeable when compared side by side. We recommend maximizing on the Cut grade, if possible.
Fancy shapes have less restrictions because beauty is in the eye of the beholder. Still, you can often safely go a grade lower with non round diamond shapes. Excellent cut fancy shapes are fairly rare.
In the end, it’s your decision and you must remember there are plenty of other factors that influence a diamond. You must choose which factors/attributes matter most to you.Shop by Cut
Diamond Brilliance: What Makes Sparkle
When diamonds are found in the earth whether as alluvial deposits or within rough, they are certainly not the well-cut shining gems that we see in jewelry. When found in the earth, diamonds actually have an opaque and rough skin on top. When polishing and cutting a diamond, this exterior skin is removed. In addition two important factors are considered. First is the refractive index of the diamond which is responsible for the brilliance of the diamond. And second is the dispersive power of the diamond which allows it's ability to split white light and reflect back additional colors. The term scintillation brilliance is applied to the number and arrangement of light reflections from the internal facets that shows of sparkle as the wearer of the diamond moves around. A diamond's fire is determined by the cut's crown height and angle and the size and number of facets on the diamond. Therefore, the angles, cut and faceting of the diamond are all essential in determining the beauty of the diamond. When considering cut, be sure to also look at the proportions of the diamond and it's measurements. This can oftentimes help you decide between two diamonds in the same cut range.
A diamond's brilliance is rather a complex integration of angles and proporations. It represents the diamond's light return based on how the light enters, bounces around and returns to the human eye. The brilliance consists of multiple factors based on faceting, and patterns. Poor light return from a diamond (diamonds that exhibit light leakage) will lack optimal beauty. They will look, darker, duller or lifeless. The best way to think about it is a window. A dirty window will make it look dull, dark or murky outside. Also, misshapen windows (concave or bent), will affect the outdoor visibility. Diamonds are similar in that without perfect faceting, the light's performance and visibility are reduced.
Fire described flashes of color resulting from spectral separation or dispersion of white light into primary colors. Fire is the reason you see blues, oranges, reds, purples, etc. in a diamond. The more colors, the better. This is similar to how light produces a visual rainbow after or during rain.
So how is the the brilliance or fire optimized in a diamond? Well, it's typically a combination of tablet facet, crown angle, girdle, pavilion depth, culet and total depth. A rule of thumb is a culet should always be closed. A table shouldn't be too large or small. Total depth shouldn't be too deep or shallow. The girrdle shouldn't be thick or very thin. And there is an inverse relationship between crown angle and pavilion angle. If the crown is steep, the pavilion angle should be shallow and vice versa. We recommend diamonds with steeper crown angles and smaller table facets for the highest degree of brilliance or sparkle.
Diamond Cut History
Within nature and in their rough state, an unpolished diamond looks significantly different than a polished diamond. In it's rough state, diamonds are not commonly used in jewelry. Initially, diamonds were simply polished in their natural shape to reveal some of the sparkle within. As years went by, cut and polish techniques were imporved to enable more light to refract and reflect within the diamond. One common diamond cut that developed in the 14th century was the point cut, in which the diamond simple took the shape of a triangle placed upon an inverted triangle. This closely mimiced it's shape in nature. Over time the importance of a culet and table was realized so that the diamond would have a more palatable shape for jewelry. However, these advancements did not create the sparkle, fire and scintillation that is seen in modern cut diamonds. In 1476 a master diamond cutter experimented with adding triangular facets to diamonds to unleash their sparkle and thus the modern diamond was on it's way to being shaped and formed. This developed into the rose or antique cut which has large and open facets that may not be symmetrical. The asymmetry is a result of diamonds being cut to preserve weight as well as hand-cutting techniques. Eventually in the 1900's a master diamond cutter named Tolkowsky acertained better diamond proportions taking sparkle and fire into consideration to produce a diamond with extraordinary brilliance. The modern brilliant cut diamond is a result of his efforts and research. Over time, diamond cut became standardized due to the efforts of diamond cutters to adhere to similiar practices and diamond cut grades. Today, diamonds are machine cut to ensure maximum precision. Varying grades can be the result of the nature of the rough diamond as well as derire to preserve carat weight and minimize the appearance of inclusions.
The Diamond's True Size or 'Spread'
Spread or the diamond's measurements is the simplest concept for a buyer to grasp. Diamond's with greater spread (less total depth) mean the diamond looks larger. Most cut grading systems don't account for spread, which is interesting given the fact that it is the easiest cut-related metric to examine.
While larger looking diamonds are not necessarily more sparkly, they are considered more desirable and often have a premium. Two diamonds can have the same carat weight, but the one with larger measurements has more spread. Spread is not related to the diamond's carat weight. It is actually the total depth percentage that dictates the spread. That means the width/length against the height. In general, we recommend diamonds in the excellent cut range with the maximum measurements so you can achieve the best of both worlds. You may pay a slight premium for this but it will be well worth it as you will be getting the best of sparkle and size.
Expert Buying Tips
Try and maximize on the cut score and grade of the diamond. This represents the sparkle of the diamond and can help mask (or make up for) lower clarity grades, color tints, or smaller than desired carat weights. You may find value in a VG cut diamond that have most of the technical aspects of a Excellent cut diamond, but missed the cut off by a technicality such as a thick girdle or larger table facet.