- CUT
As one of the 4C's used to describe and determine diamond quality, cut references how well a diamond's facets interact with light. Though it's often confused with shape, which refers to the external outline of a diamond (such as round, oval, or pear), cut is actually responsible for a diamond's ability to transmit light and sparkle.
Why is Cut Important
Cut is a crucial factor to consider when selecting a diamond, as it is accountable for its sparkle. An excellently cut diamond will deliver the classic, unmistakable light show you expect from a diamond. A poorly cut diamond, on the other hand, will be much duller. As cut can significantly impact the appearance of a diamond and the light it emits, it's essential to understand what it is and how it's graded.
How is Diamond Cut Graded
The Gemological Institute of America (GIA) has extensively studied how light interacts with round brilliant cut diamonds to better understand the factors that contribute to their appearance and sparkle. The result of their studies was the GIA Cut Grading System, which standardizes and evaluates cut quality on appearance (brilliance, fire, scintillation), design (proportion), and craftsmanship (polish, symmetry). Their cut scale ranges from Ideal, Excellent to Very Good, Good, Fair, and Poor.
An Ideal cut diamond's proportions must be within the ideal range, and polish and symmetry must be of the highest grade.
An Excellent cut diamond's proportion, polish, and symmetry have all received a top grade (known by the GIA/IGI as Triple Excellent). These are the highest-quality stones and feature incredible, eye-catching sparkle.
A Very Good cut diamond's proportions are just outside of the excellent range, and polish and symmetry can range from the highest grades to more moderate levels. These diamonds can present an incredible sparkle at a more accessible price point.
A Good cut diamond's proportions will be only slightly imperfect, allowing for plenty of light to reflect light. However, good-cut diamonds will not be as bright as higher-cut grades, as flawed ratios will leave more dark spaces in the stone, causing it to look duller. Depending on the balance of the other 4 C's, good-cut diamonds will generally feature a more accessible price point.
A Fair cut diamond has little light refraction compared to diamonds with higher cut grades. This is caused by gray areas surrounding the crown or areas of darkness or dullness within the table, girdle, or both. While Fair cut diamonds will be more accessible from a price point perspective, their lack of sparkle deters many customers from selecting them.
Poor cut diamonds are generally not recommended as light spills from their pavilion, culet, or both. They will show a marked reduction in fire and scintillation from those with higher cut grades, as the dark areas are prominent and distracting. Please note that Brilliant Earth does not carry Poor-cut diamonds.
2. Colour
Color references the absence of color within a diamond. The scale ranges from D (colorless) to Z. Diamonds outside this range are considered 'fancy colored.'
D, E, and F are colorless grades. D and E-colored diamonds have virtually no color, and F diamonds have a nearly undetectable amount of color that shows only in the face-down position (when the diamond is viewed from the bottom). These icy-white diamonds are the rarest and the highest quality in color.
D-color is the highest color grade awarded only to completely colorless diamonds. To the naked eye, D color diamonds feature an icy whiteness that contains no color at all.
E-color diamonds are colorless and appear almost identical to D-color diamonds. The majority of the time, the difference between these two grades is only visible to an expert gemologist.
F-color diamonds are also colorless and appear almost identical to D and E-color diamonds. Generally, only an expert gemologist or trained professional can distinguish between a D, E, and F-color diamond when viewing them from a top-down position.
Colorless diamonds are the rarest and most expensive white diamonds, as they are considered the highest quality on the GIA color scale. Since only an expert can easily tell the difference between a D, E, or F-colored diamond, they all make for top-notch, premium options when considering which color is best for you.
3. CARAT
The third most important quality is carat. Carat is a measurement unit that describes a diamond's weight, not its size. One carat is roughly the weight of a paperclip.
One carat is 200 milligrams, and each carat is divided into 100 ‘points’ to allow exact measurements to the thousandth decimal place. To ensure precision, accuracy, and consistency, diamond carat is measured by professionals with specialized micro-balance scales.
CTTW, TCW, and TW are all abbreviations for ‘Carat Total Weight.’ CTTW references the combined weight of all diamonds within a piece (or pair) of jewelry where more than one diamond is used. Diamond stud earrings, for example, are typically quoted in CTTW, which indicates the combined weight of both earrings within the pair.
4. CLARITY
Clarity is the absence of internal inclusions and surface blemishes on a diamond. The scale ranges from Internally Flawless to Included.
Flawless (FL): No inclusions and no blemishes visible under 10x magnification. Less than 1% of all diamonds are FL clarity, as it is nearly impossible to find a diamond that is completely inclusion-free.
Internal Flawless (IF): No inclusions are visible under 10x magnification. Some small surface blemishes may be present under a microscope.
Very, Very Slightly Included (VVS1 and VVS2): Inclusions are characterized as minute and are so slight that they are difficult for a skilled grader to see under 10x magnification.
Slightly Included (SI1 and SI2): Inclusions are observed with effort under 10x magnification but can be characterized as minor.
Included (I1, I2, I3): Inclusions are obvious under 10x magnification, which may affect transparency and brilliance.
