Diamond Cut vs Diamond Shape vs Diamond Cut Grade

Let's clear up a common confusion: diamond cut is not the same as diamond shape. While many people use these terms interchangeably, they're quite different. There are three different things that are usually referred to when people talk about diamond cut:  

• Diamond Cut Grade: A technical assessment of how effectively the diamond reflects light, typically ranging from Excellent to Poor
  
  
• Diamond cutting style: There are three main diamond cutting styles: brilliant, step and mixed cut. They focus on the diamonds facets, symmetry, and dimensions. 
  
  
• Diamond Shape: The geometric outline of the diamond (round, princess, oval, etc.)

Example: If a diamond is “round brilliant” - “round” is the shape and “brilliant” is the diamond cutting style. In addition to that, the diamond gets a cut grade. For example “excellent”. See image below (Picture source: IGI):

Why is Diamond Cut Important?

The cut of a diamond is arguably the most crucial factor of the 4Cs (cut, color, clarity, carat) in determining its beauty and brilliance. A well-cut diamond will:

• Maximize light performance, brilliance, sparkle, and fire by allowing light to interact with the facets in an optimal way, creating intense sparkle.
• Enhance the stone's overall appearance, shape, and symmetry, making it look more proportionate, balanced, and visually appealing.
• Appear larger and more brilliant than a poorly cut diamond, as a well-cut diamond makes the most efficient use of its carat weight, often appearing more substantial and lively.

Did you know: Unlike natural diamonds, which are constrained by their rough formation, lab diamonds can be cut with extraordinary precision. This means lab diamonds can achieve superior cut quality more consistently and affordably. 

Cut Grade: The Diamond Cut Scale

Diamond cut is typically graded on a scale from Poor to Excellent (or ideal), applicable to both lab-created and natural diamonds:

• Poor: Significant light leakage; minimal brilliance
• Fair: Reflects some light; low brilliance
• Good: Decent light reflection; moderate brilliance
• Very Good: Excellent reflection; strong brilliance and fire
• Excellent: Maximum light return; exceptional brilliance and fire

The process of determining a diamond’s cut grade is complex, involving precise measurements and calculations. While you don’t need to understand the process, it’s essential to understand that an excellent cut diamond (sometimes also referred to as "ideal") reflects almost all the light that enters it, maximizing sparkle, brilliance, and fire.

Diamond cut: excellent vs ideal

While there are standardized scales for diamond color and clarity, the scale for diamond cut can vary between grading laboratories:

• The AGS (American Gem Society), IGI (International Gemological Institute), and GCAL (Gem Certification and Assurance Lab) include the category “Ideal”, which represents the highest possible cut quality. This grade is followed by "excellent", all the way down to "poor".  
• The GIA (Gemological Institute of America) grade scale does not include "ideal". Their highest grade is "excellent". 

Did you know? Most diamond laboratories assign a formal cut grade only to round brilliant diamonds, as they are the only ones to have standardized facets. Other shapes, known as fancy shapes (e.g., princess, emerald, cushion), do not receive a formal cut grade. They do not have standardized facets and are more subjectively evaluated.

What determines cut level

The cut grade is determined by evaluating a diamond’s proportions, symmetry, polish, weight ratio, and durability, as these directly affect its light performance—specifically its brilliance, fire, and scintillation. Key factors include:

• Table size
• Crown and pavilion angles
• Girdle thickness
• Culet size

These elements work together to ensure optimal light reflection and refraction, which is why cut is a critical factor in a diamond's overall appearance.

Diamond Cut Types: Brilliant, Step, and Mixed Cuts

Diamond cutting styles play a crucial role in shaping a stone’s brilliance, appearance, and overall appeal. The three primary cutting styles—brilliant cut, step cut, and mixed cut—each offer unique characteristics and are suited for different diamond shapes and preferences.

Brilliant Cut

• Maximizes light return and sparkle through a symmetrical arrangement of facets designed for optimal brilliance.
• Primarily used for round diamonds, but other shapes with a brilliant-style facet arrangement (e.g., oval, pear, marquise, and heart) are referred to as “modified brilliant cuts.”
• Designed to reflect the most light through the top (table) of the diamond, creating dazzling brilliance and fire.
• Known for its versatility and is the most popular cut for engagement rings.

Step Cut

• Features long, flat, rectangular facets arranged in parallel steps along the pavilion and crown.
• Creates a sophisticated hall-of-mirrors effect, emphasizing clarity and color over sparkle.
• Commonly used in shapes like emerald and baguette cuts, as well as the Asscher cut (a square variation of the step cut).
• Less sparkly than brilliant cuts but highly valued for their clean, elegant appearance and ability to showcase a diamond’s natural qualities.

Mixed Cut

• Combines elements of brilliant and step cuts, offering the sparkle of the brilliant cut with the structured appearance of the step cut.
• Balances brilliance and a unique geometric appearance, making it versatile and contemporary.
• Often used in princess cuts (square shape with brilliant-style facets) and cushion cuts (a rounded square or rectangular shape with brilliant-style or hybrid facets).
• Allows for creative designs that emphasize both light performance and shape.

Diamond Shapes and Their Cut Types

When exploring the world of diamonds, understanding the difference in diamond cuts is crucial for making an informed choice. Diamonds are crafted into various diamond cut types, each designed to enhance their brilliance, fire, and unique beauty. From round brilliants to emerald step cuts, the diamond cut differences lie in the arrangement of facets, light performance, and overall appearance. In this guide, we’ll dive into the most popular diamond cut names, exploring how each shape relates to its cutting style and what makes it distinct.

*Radiant: This cut can fall under both brilliant and mixed cut categories because it combines brilliant-style facets with a rectangular or square outline.

*Fancy Shapes: Most cuts outside of round brilliant are referred to as "fancy shapes." 

Did you know? The price of a diamond depends significantly on how much raw material is used and how much is lost during the cutting process. However, with lab-grown diamonds, the growth process can be optimized to create shapes closer to the final cut, minimizing material waste. This efficiency reduces production costs, contributing to the lower price tag of lab-grown diamonds compared to natural ones.

Lab Diamonds and Cut Grades

Lab diamonds offer a remarkable advantage in both cut quality and affordability:

• Precise technological cutting processes: Advanced machinery ensures accuracy and minimizes waste.
• Consistent quality control: Uniform growth conditions lead to predictable rough diamond characteristics, making it easier to achieve excellent cuts.
• Lower production costs: The controlled environment and efficient cutting processes reduce overall expenses.
• No mining-related expenses: Eliminating the need for extraction avoids associated costs and environmental impact.
• Superior cut grades: Lab diamonds can be consistently cut to maximize brilliance, fire, and symmetry.
• Optimized Shapes: Lab diamonds are grown in predictable shapes that minimize material loss during cutting, making them more affordable without compromising quality. 
• Environmental Impact: Unlike natural diamonds, lab diamonds are created without mining, drastically reducing their environmental footprint and making them a more eco-friendly choice.

Did you know? Lab diamond cutting technologies can achieve near-perfect symmetry and precision that would be incredibly rare and expensive in natural diamonds.

Diamond Cut and the 4Cs

• Clarity focuses on internal and surface imperfections (inclusions and blemishes), while cut determines how light interacts with the diamond.
• A high-quality cut can enhance light performance, making inclusions less noticeable and the diamond appear more brilliant, even with a lower clarity grade on the clarity scale.

• Color of a white diamond can range from clear to slightly yellow.
• An exceptional cut can improve a diamond’s visual appearance, making it seem whiter and brighter by maximizing light return and dispersion.
• A well-cut diamond can partially offset the appearance of lower color grades, especially in near-colorless diamonds.

• Cut quality significantly influences a diamond’s beauty, often more than its size (carat weight).
• A smaller diamond with an excellent cut can appear more brilliant and sparkly than a larger diamond with a poor cut, as light performance is maximized in a well-cut stone.

Pro Tip: Always prioritize cut quality over size or other factors when selecting a diamond. A well-cut diamond will always be more beautiful and valuable.

How Diamonds Are Cut

Diamonds are cut through a meticulous process that transforms rough stones into dazzling gems.

1. The process begins with planning, where experts analyze the rough diamond to determine the best shape and maximize carat weight.
2. Next, the diamond is marked and cleaved or sawn into smaller pieces using various diamond cutting tools.
3. Faceting follows, where precise angles are cut into the diamond’s surface to optimize light performance.
4. Finally, the diamond is polished to achieve its signature brilliance and symmetry. 

This combination of artistry and technology ensures each diamond reflects light beautifully and achieves its intended shape and style.

Natural vs. Lab-Grown Diamonds:

• Natural Diamonds: Rough stones are unpredictable in shape, making planning and cutting more challenging and resulting in significant material loss.
• Lab-Grown Diamonds: Created in controlled conditions, these diamonds often grow in shapes optimized for cutting, reducing waste and achieving higher precision in cuts.

This distinction in starting material gives lab-grown diamonds an edge in affordability and consistency without compromising quality.

Created Forever Lab grown diamonds

At Created Forever, we are committed to offering only the finest quality lab-grown diamonds. We exclusively carry diamonds that are graded “Very Good” or better for cut quality, ensuring that each stone reflects maximum brilliance, fire, and scintillation. Our lab diamonds are crafted with precision using the latest technology, guaranteeing consistent quality and beauty. By focusing on high-grade diamonds, we offer our customers exceptional value and the assurance that their diamond will shine brightly for years to come.

Frequently Asked Questions