The cut of a diamond not only refers to the diamond’s shape, it also refers to how effectively the diamond returns light back to the viewer’s eye. A well-cut diamond will appear very brilliant and fiery, while a poorly cut diamond can appear dark and lifeless, regardless of its color or clarity.
Not only do well-cut diamonds appear more brilliant, they also tend to appear larger than other diamonds of the same carat weight. An "ideal" diamond has both increased brilliance and diameter relative to more deeply-cut diamonds.
Excellent cut diamonds
An Excellent Cut Diamond is a round, brilliant, or princess cut diamond that is cut to ideal proportions and angles, and has excellent polish and symmetry ratings. An Excellent Cut Diamond is perfectly proportioned to refract light, producing that fire and brilliance up through to the table and crown.
Understanding Brilliance, Dispersion & Scintillation
A well-cut diamonds exhibit three different properties: brilliance, dispersion and scintillation. As light strikes a diamond's surface, it will either reflect off the table of a polished stone or enter the diamond. The light that is reflected off the diamond is known as the diamond's brilliance. As light travels through a stone, some of the light rays are separated into flashes of color. This is known as dispersion. The result of dispersion is the separation of white light into its spectral colors is known as fire. Scintillation is flashes of color that are viewable as an observer moves a diamond back and forth.
When shopping for a diamond, it is generally preferred to choose a stone with the least amount of color possible. Diamond color is graded on a scale from D-Z and is divided into five broad categories (colorless, near colorless, faint, very light and light). Diamonds come in all colors of the spectrum. The predominant color you see in a diamond is yellow, which is caused by the trace element nitrogen.
Generally, when comparing color between two diamonds, the diamonds need to be at least two color grades apart to even begin to see a difference. As you can see from the images below, when diamonds are in the face up position it is almost impossible to see any color. When viewing the diamond from the side profile, you may start to detect some color; however, diamonds are admired for their beauty from the face up position and not the side.
Diamonds within the colorless range(D-F) are the most rare and valuable of all those on the color scale. D/E color stones display virtually no color, whereas F colored diamonds will display a nearly undetected amount of color when viewed face down by a gemologist.
Diamonds within the near colorless range (G-J) appear colorless in the face up position, but do display a slight amount of color when viewed face down against a perfectly white background. This trace amount of color will be undetectable to an untrained eye once the diamond has been mounted. Near colorless diamonds offer a tremendous value for their price.
Diamonds within the faint color category(K-M) may show a slight hint color when viewed in the face up position; however, these are another wonderful option for those who are not sensitive to color. Some even love the color scheme that is displayed from these diamonds.
Fancy yellow diamonds (also known as canary diamonds) are the most well-known of all fancy diamonds. Although many white diamonds appear yellow and are listed on the far end of the standard diamond color scale, they are not considered fancy yellow diamonds.
A yellow diamond is considered fancy when it is graded according to the terms: light yellow, fancy light yellow, fancy yellow, fancy intense yellow, fancy dark yellow, fancy deep yellow, and fancy vivid yellow.
Roughly 60% of all fancy color diamonds are yellow diamonds. Yellow diamonds contain nitrogen, which is responsible for giving the diamond its yellow color.
Benz & Co Diamonds offers a wide selection of fancy yellow diamonds, in a variety of shapes and carat sizes. Yellow diamonds are a great option when looking to add to your diamond selection and appear especially striking when set in a platinum or white gold setting.
It is important to select a diamond that does not have any inclusions that will affect the overall beauty and durability of the diamond. If you want to be 100% sure that your diamond will be completely clean of "eye-visible" inclusions, stick with diamonds graded "VS2" or higher. Shopping for SI quality diamonds can be very rewarding, it's best to choose an SI quality diamond from the "Pre Set Engagement Ring" category because these diamonds handpicked by our experts from thousands of SI quality diamonds in order to find the right one, the one that will look as clean as possible and give you the best value for your money.
It is also a good idea to balance the clarity grade of your diamond with the color. If you are looking at diamonds in the D-F color range, focus on clarity grades of VS2 or higher. Diamonds in the G-I color range combined with SI clarity are excellent values!
Carat is a term that refers to the weight of a diamond. Prior to the twentieth century, diamonds were measured using carob seeds, which were small and uniform and served as a perfect counter weight to the diamond. The word "carob” is the origin of the word "carat" that we use today.
Diamond Size and Diamond Carat Weight
The size of a diamond is proportional to its carat weight. When rough diamonds are cut and polished into finished diamonds, up to 2/3 of the total carat weight may be lost. Since larger rough gems of high quality are found less frequently than smaller rough gems of high quality, a single two carat diamond will be more expensive than two one-carat diamonds of the same quality.
In the United States, the majority of diamonds used in jewelry and sold as loose diamonds are one carat or less in weight. The average engagement ring diamond sold in the U.S. is less than 1/2 carat in weight.
A diamond will increase in weight much faster than it increases in actual "face-up" diameter. For example, while an ideal cut 1 ct diamond measures approximately 6.5mm in width, a diamond of twice its weight measures only 8.2mm wide—less than a 30% increase.