Cut
The Cut of the diamond is completely determined by the precision and quality of the methods used to cut and polish the diamond. The only shape that receives an internationally-recognized cut grade is a round brilliant. There is typically no “cut” grade provided to other shapes such as ovals, emeralds, pears, etc.
Note that “Diamond Cut” does not refer to the shape or make of the diamond gemstone. The shapes that Ada offers can be seen here.
The Five Cut Grades
Gemological laboratories have 5 grades of cut: Ideal, Excellent, Very Good, Fair, and Poor. Ada Diamonds only offers round diamonds with an Excellent or Ideal cut.
Light Dances Within the Diamond
To understand the differences between an excellent cut diamond and a mediocre cut diamond, you must first understand how light interacts with diamond, as light is reflected and refracted in a very different way than in air, water, glass, or other gemstones. Diamond has a very high refractive index: light slows down in diamond, which creates the brilliance that sets diamonds apart.
The Elements of Cut
BRIGHTNESS is how much light you see when you view a diamond. A well-cut diamond has very specific dimensions that reflect and return virtually all of the light that enters the diamond back out of the top of the diamond. Even in poor lighting, a diamond can appear very bright. A poorly-cut diamond leaks light out of the bottom and is dull or flat when compared to a well-cut diamond.
FIRE describes the rainbow of colors reflected by the diamond gemstone. Diamond has an extremely high rate of light dispersion. When white light enters the diamond, it is spread apart into distinct colors in a prism-like effect.
SCINTILLATION defines the flashes of light that you see when the diamond moves. This is also called the sparkle of the diamond.
PATTERN is the contrasting light and dark areas in a diamond gemstone. The better the cut of the diamond, the better the contrast is between dark areas and light areas. Mediocre diamonds have blurry gray areas, whereas the best-cut diamonds have very distinct contrasting patterns that are uniform throughout the diamond. Ada Diamonds is proud to offer special inventory of round brilliants that received a special hearts and arrows designation by IGI or GCAL.
The Make of a Fancy Shape
Not apparent on a grading report is the “make,” or the way a fancy-shaped diamond looks in person. There is information on a grading report such as pavilion depth, symmetry, and polish that help an expert determine whether a fancy-shaped diamond will look gorgeous in person. However, you should never buy a fancy-shaped diamond sight unseen. Characteristics such as bow ties, paneling, and light leakage are only visible in person, not with a certificate or with a 360 video. The best way to ensure a gorgeous make of your diamond is to have a lab diamond expert inspect it before sale.
