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The King of the 4Cs

Diamond Cut Grade

Cut is the only factor that fuels a diamond's fire, sparkle, and brilliance. It is widely considered the most important of the 4Cs.

The Anatomy of Sparkle

When a diamond is cut to ideal proportions, it bends and reflects light in three specific ways.

Brilliance

The white light reflected from the surface and inside the diamond. This creates the primary brightness of the stone.

Fire

The scattering of white light into all the colors of the rainbow. This dispersion gives the diamond its magical, colorful flashes.

Scintillation

The amount of sparkle a diamond produces, and the pattern of light and dark areas caused by reflections within the diamond.

The Cut Grading Scale

Ideal / Super Ideal

Represents the top 3% of diamonds. Reflects nearly all light that enters the diamond. The rarest and most brilliant cut.

Excellent

Reflects almost as much light as an Ideal cut but at a lower price point. An outstanding choice for engagement rings.

Very Good

Reflects most light that enters. Appears very similar to Excellent cuts to the naked eye but often has slightly wider proportions.

Good

Reflects much of the light. A great option for budget-conscious buyers who want to maximize carat weight.

Fair / Poor

Allows most light to escape from the sides or bottom. The diamond appears dull and lifeless. We do not carry these grades.

It's All About Proportions

For a Round Brilliant diamond, two key ratios determine its cut grade: Depth % and Table %.

Ideal Depth (59% - 62.6%)

The height of the diamond measured from the culet to the table. If too deep or too shallow, light escapes through the sides.

Ideal Table (53% - 58%)

The width of the top flat facet relative to the diamond's total width. This acts as the window for light to enter.

Table %Depth %

Our Recommendation

For the best balance of beauty and value, we recommend selecting an Excellent or Ideal cut grade. This ensures your diamond will sparkle brilliantly, even in low light.

Shop Ideal Cut Diamonds

Understanding Diamond Cut Quality

Of all the 4Cs — cut, color, clarity, and carat — cut is the most important factor in determining a diamond's beauty. A well-cut diamond interacts with light in ways that produce the stunning brilliance and sparkle diamonds are famous for. Even a diamond with exceptional color and clarity will appear dull if it is poorly cut, while a well-cut diamond of modest color and clarity can look breathtaking.

Cut Grade Scale

Ideal / Excellent — The highest cut grade. The diamond is precisely proportioned and polished to maximize light return. It exhibits exceptional brilliance, fire, and scintillation. Recommended for the most discerning buyers.

Very Good — Reflects nearly as much light as an Ideal cut. Slight deviations from optimal proportions result in minimal loss of brilliance. Offers excellent value at a lower price point than Ideal.

Good — Reflects most light that enters the diamond. The proportions fall outside the Very Good range but still produce an attractive stone. A reasonable choice for buyers prioritizing other factors like carat weight.

Fair — Some light escapes through the sides or bottom of the diamond. Noticeable reduction in brilliance and sparkle compared to higher grades. Generally not recommended for center stones.

Poor — Significant light loss results in a noticeably dull or glassy appearance. Poor cuts are rarely found in fine jewelry retail and should be avoided.

How Cut Affects Brilliance

A diamond's cut determines how effectively it handles light. Brilliance refers to the total amount of white light reflected from the diamond — both internal and external reflections. Fire describes the dispersion of light into its spectral colors, creating flashes of color seen from different angles. Scintillation is the pattern of light and dark areas and the sparkle produced when the diamond, the light source, or the observer moves. An Ideal or Excellent cut diamond achieves a precise balance of all three optical properties, making it appear alive with light from every angle.