Diamond Guide: Cut

The Diamond Guide: Cut

What Is Diamond Cut?

As one of the 4 C’s used to describe and determine diamond quality, cut refers to how well a diamond’s facets interact with light. It is often confused with shape, which is the external outline of a diamond (such as round, oval, or pear). However, cut actually influences a diamond’s ability to transmit light and produce sparkle. Achieving the right cut requires precise artistry and craftsmanship to ensure the diamond’s proportions, symmetry, and polish maximise light return and shine. The better the cut, the more sparkle a diamond will exhibit.

Why Is Cut Important?

Cut is a vital factor to consider when selecting a diamond, as it directly affects the sparkle and brilliance of the stone. A diamond with an excellent cut will produce the classic, dazzling light display you’re accustomed to, while a poorly cut diamond will appear dull and lackluster. Since the cut plays a significant role in how a diamond reflects light and how it looks overall, understanding how it is graded is essential when choosing the perfect diamond.

How Is Diamond Cut Graded?

The Gemological Institute of America (GIA) has conducted extensive research to understand how light interacts with round brilliant cut diamonds, leading to the development of the GIA Cut Grading System. This system evaluates a diamond’s cut quality based on three main factors: appearance (including brilliance, fire, and scintillation), design (proportion), and craftsmanship (polish and symmetry). The GIA Cut Grading scale ranges from Excellent to Very Good, Good, Fair, and Poor.

Other independent gemological institutes have their own ranking systems for diamond cut. For instance, the International Gemological Institute (IGI) adds an extra rank above Excellent, calling their highest-quality diamonds “Ideal.”

Characteristics Of Cut

Polish

Polish refers to the quality of a diamond’s external surface, which is the result of the polishing process. The presence of imperfections such as pits or nicks is considered when evaluating polish. Diamonds are graded on a scale from Ideal or Excellent to Poor, and this grading is typically listed on the diamond certificate.

Symmetry

Symmetry indicates the precision of a diamond’s external shape and the even arrangement of its facets. This can be divided into two categories: proportion-related symmetry (external) and facet-related symmetry (internal). Like polish, symmetry is graded on a scale ranging from Ideal or Excellent to Poor and is usually included on a diamond certificate.

Proportion

Proportion refers to the measurement of a diamond’s crown and pavilion angles, as well as the overall dimensions of its facets. Since facets act like tiny mirrors, their proportions greatly influence a diamond’s face-up appearance. Proper proportions also help professionals assess how well a diamond will sparkle.

Brilliance

Brilliance, also known as brightness, is the white light reflected from both the interior and exterior of a diamond. When light enters the diamond, its internal facets reflect it in various directions based on their angles and tilt. A well-cut diamond displays superior brilliance, bouncing light off multiple facet surfaces for a bright and lively appearance.

Fire

Fire refers to the dispersion of white light into the full spectrum of rainbow colors. Diamonds excel in scattering light and showcasing sparks of red, orange, yellow, green, or blue. For fire to be prominent, diamonds must be cut precisely; poor cuts allow light to escape too early, preventing the rainbow of colors from appearing.

Scintillation

Scintillation is the sparkle produced by a diamond when it moves in the light. The facets split the incoming white light into a spectrum of colors, creating sparkling flashes that seem to dance across the diamond’s surface. These flashes are contrasted by darker, colored reflections from the internal facets, with the balance between light and dark areas creating the overall sparkle.

Grades

Now that you have a better understanding of the characteristics involved in determining a diamond’s cut grade, let’s explore the scale to help you select the perfect diamond.

Excellent

A Super Ideal cut diamond boasts top-grade proportions, polish, and symmetry (often referred to as Triple Excellent by GIA/IGI). These diamonds represent the highest quality and deliver stunning, eye-catching sparkle.

Very Good

A Very Good cut diamond’s proportions fall just outside the ideal range, with polish and symmetry varying from the highest grades to more moderate levels. These diamonds still deliver incredible sparkle, offering great value at a more accessible price.

Good

A Good cut diamond’s proportions are slightly imperfect, but still allow ample light reflection. While it won’t have the same brightness as higher-grade cuts, good-cut diamonds offer great value and can be a more affordable option, depending on the balance of the other 4 C’s.

Fair

A Fair cut diamond lacks the light refraction of higher-grade diamonds. Gray areas or darkness within the table, girdle, or crown lead to reduced sparkle. While these diamonds can be more affordable, their lack of brilliance makes them less desirable for many customers.

Poor

Poor cut diamonds are generally not recommended, as light escapes through the pavilion or culet, resulting in a significant loss of fire and scintillation. Dark areas become prominent and detract from the overall appearance. We do not recommend or sell does not carry Poor cut diamonds.

Pricing

How Does Diamond Cut impart the price of a stone?

Grades across all of the 4 C’s, including cut, can significantly affect a diamond’s price. In general, diamonds with higher cut grades come at a higher price due to the level of craftsmanship and attention to detail required for their creation. Choosing the right diamond is often a balancing act between your budget and the qualities you value most in a stone.

For instance, if sparkle is your top priority, you might choose to prioritize a higher cut grade and adjust other factors, like carat, color, or clarity, to stay within your budget. This allows you to get the brilliance you desire without overspending on other attributes.