What is the best cut for a diamond?

The best cut grade is Excellent (or Ideal ), especially for round brilliant diamonds,, as it delivers the most brilliance, fire, and sparkle.

How is diamond cut different from diamond shape?

Cut refers to how well a diamond’s facets are proportioned and polished, affecting how it reflects light. Shape refers to the outline of the diamond, such as round, oval, or emerald.

Does diamond cut affect sparkle?

Absolutely. Cut is the most important factor for sparkle, a well-cut diamond reflects more light and looks more brilliant, even at smaller sizes.

Is diamond cut more important than clarity or carat?

In most cases, yes. A well-cut diamond will look brighter, more dazzling, and even larger than a poorly cut diamond with higher clarity or carat weight.

What Is Diamond Cut? Why Cut Quality Matters Most

What Is Diamond Cut? Why Diamond Cut Quality Matters Most

When it comes to diamonds, diamond cut is everything. Unlike the other Cs, carat, colour, and clarity, which describe the diamond's natural features, cut is about diamond craftsmanship. It’s the only factor in a diamond’s beauty shaped entirely by human hands.

A diamond’s cut determines how it interacts with light. In essence, the diamond cut quality is what gives a diamond its sparkle, brilliance, and fire, making it come to life.

Diamond Cut vs. Diamond Shape: Understanding the Difference

Diamond shape refers to the stone’s outline, such as round, oval, pear, or emerald. Diamond cut, however, refers to how the facets are arranged, the proportions, and how these affect the diamond’s brilliance, fire, and scintillation.

Simply put, diamond shape is what you see, while diamond cut is what makes it shine.

While “cut” and “shape” are sometimes used interchangeably in casual talk, they mean different things in diamond grading. Shape is just the external outline, but diamond cut quality refers to the precision of the internal craftsmanship that controls the diamond’s sparkle.

How Are Diamonds Cut? The Craft Behind Diamond Brilliance

Cutting a diamond requires expert craftsmanship, precision, and artistry. Every angle and proportion matters. When executed perfectly, the diamond reflects and refracts light beautifully, producing maximum brilliance and sparkle.

The classic round brilliant cut, with its 57 or 58 facets, is the only shape with an official diamond cut grade from gemological labs like the GIA. Other shapes, called fancy cuts, including oval, marquise, emerald, pear, and heart, don’t receive formal cut grades but are evaluated for proportions and symmetry, which impact their visual performance.

Even without official grading, a well-cut fancy shape can deliver stunning brilliance and is assessed by expert gemologists for its cut quality.

What Makes a Great Diamond Cut? Key Factors to Consider

A diamond’s cut quality depends on three essential factors:

Proportions
This refers to the relationship between the parts of a diamond — such as depth, table size, crown angle, and pavilion. These proportions control how light travels inside the diamond. A well-balanced set of proportions leads to a diamond with exceptional brilliance.
Symmetry
Symmetry measures how precisely the facets align. Minor misalignments can reduce how well light bounces inside the diamond, affecting its sparkle.
Polish
Polish describes the smoothness of the diamond’s facets. A well-polished diamond reflects light cleanly, boosting its brilliance and shine.

Why Diamond Cut Is the Key to Brilliance and Sparkle

Diamond cut is crucial to a diamond’s sparkle. It’s not just about shape, it’s about the angles, proportions, and symmetry of each facet that control how light is reflected and refracted. A well-cut diamond maximises light performance, producing exceptional brilliance, fire, and scintillation. The skill of the diamond cutter directly influences how well these facets work together to enhance the stone’s beauty.

Diamond Cut Grading Explained: From Excellent to Poor

Official diamond cut grades apply only to round brilliant diamonds and range from Excellent to Poor. These grades assess how well the diamond’s proportions, symmetry, and polish combine to reflect light:

Excellent: Ideal proportions, perfect symmetry, and polish, reflecting light beautifully for maximum sparkle.
Very Good: High-quality cut with great brilliance and fire; minor imperfections rarely noticeable.
Good: Decent sparkle with slight imperfections affecting brilliance.
Fair: Noticeable flaws reduce light reflection and sparkle.
Poor: Poorly cut with dull appearance and minimal sparkle.

Other diamond shapes do not receive official cut grades but are evaluated visually by experts.

Brilliance, Fire, and Scintillation: The Sparkle You See

When a diamond flashes bright light or rainbow glimmers as it moves, you’re witnessing a high-quality cut’s effects. These three phenomena create the diamond’s iconic sparkle:

Brilliance: The bright white light reflected internally and externally.
Fire: Rainbow flashes of colour caused by light dispersion.
Scintillation: The sparkle of light and dark flashes as the diamond moves.

The combination of brilliance, fire, and scintillation gives a diamond its lively, energetic sparkle, all dependent on the cut.

How Diamond Cut Affects Value and Appearance

Cut is often the most critical factor in a diamond’s value. Two diamonds with the same carat, colour, and clarity can look dramatically different due to cut quality. A well-cut diamond appears more brilliant and often larger than a poorly cut one, making cut quality essential to prioritise.

Are Lab-Grown Diamonds Cut Differently from Natural Diamonds?

No. Lab-grown diamonds and natural diamonds are cut using the same techniques and standards. The cutting process reveals a diamond’s full potential for brilliance, regardless of its origin.

True Brilliance’s Commitment to Cut Quality

At True Brilliance, we uphold the highest standards of diamond cut quality. Every diamond undergoes a thorough evaluation to ensure it performs brilliantly in terms of sparkle, fire, and scintillation, giving you exceptional value and beauty.

We believe the cut is the single most important factor in a diamond’s appearance, and we carefully select stones that showcase expert craftsmanship and optimal light performance.

Why Diamond Cut Matters Most: The Secret to a Diamond’s True Beauty

The diamond cut is the key to unlocking a stone’s true radiance. It’s about how the facets interact with light, not just the shape. A superior cut enhances reflection and refraction, bringing out the diamond’s dazzling sparkle.

When choosing a diamond, whether natural or lab-grown, understanding diamond cut quality ensures you select a stone that truly shines, not just one that looks good on paper.

The cut is the secret behind every diamond’s brilliance, fire, and scintillation. It brings a diamond to life, capturing light and transforming it into unforgettable sparkle. Prioritise cut , it’s what makes your diamond genuinely exceptional.

Understanding the 4Cs: Diamond Cut