When selecting lab grown diamond engagement rings, understanding the 4 C's—Carat, Cut, Color, and Clarity—is crucial. These primary attributes determine a diamond's visual appeal, size, and quality. Graded and categorized by the Gemological Institute of America (GIA), these characteristics help distinguish between similar diamonds and establish their value and price. The GIA's standardized grading scales enable accurate identification for both consumers and gemologists. Mastering the 4 C's allows you to choose a diamond that fits your budget while maximizing quality and size. This guide will educate you on the basics, ensuring you know what to look for and how to evaluate a diamond's quality and value effectively.

Carat: The Most Visual C - Size

When considering lab grown diamond engagement rings, Carat is the most visually impactful attribute, representing the diamond's weight and size. A larger diamond is rarer and more valuable. Carat should not be confused with karat, which measures gold purity; a 1.00 carat (ct) diamond weighs 0.20 grams. Diamonds are measured in millimeters by their length and width (or diameter). On average, mining 250 tons of rock produces just 1.00ct of diamond, highlighting their rarity and cost.


Diamonds within each carat range have standard millimeter sizes, allowing you to approximate their visual dimensions. Precision cutting, often by machine, ensures these measurements are consistent, especially for round diamonds, which typically have less depth compared to other shapes. Understanding a diamond's size involves evaluating its measurements.

diamond carat size chart

Diamond prices increase exponentially with carat weight. Critical weight milestones such as 0.30ct, 0.40ct, 0.50ct, 0.70ct, 0.90ct, 1.00ct, 1.50ct, 2.00ct, 3.00ct, 4.00ct, 5.00ct, and 10.00ct significantly impact pricing, with cutters striving to meet or exceed these weights. 


The average diamond carat weight is 0.90ct, making it the most preferred C among consumers due to its visual prominence. When budgeting for a diamond, consider carat alongside the other 3 C's (Cut, Color, and Clarity). Increasing carat might necessitate compromises in the other C's and vice versa to fit within your budget.

Cut: The Diamond's Sparkle

When selecting lab grown diamond engagement rings, the cut is crucial as it maximizes the diamond's sparkle, fire, and brilliance. The cut determines how light interacts with the diamond, creating the dazzling sparkle seen when light penetrates, bounces within, and reflects back to the eye. The precision of the angles, locations, sizes, and shapes of the diamond’s facets directly impacts its light performance and sparkle.

diamond cut guide chart

**Fair & Poor**: Diamonds in this category exhibit significant light leakage due to being too deep or shallow, resulting in minimal brilliance and visual appeal. These cuts fall within the top 35% of gem-quality diamonds but do not meet With Clarity's light performance criteria, making them less suitable for sparkling jewelry.

**Good**: Well-cut diamonds that capture light effectively, though they may have some light leakage. These diamonds represent the top 25% of diamonds and offer a high degree of sparkle. Good cut diamonds can vary in size and appearance, so consulting a gemologist is recommended to ensure you get the best value and look.

**Very Good**: These diamonds capture almost all their potential brilliance with minimal light leakage, often achieving this grade to balance other characteristics like Color, Clarity, or Carat. Representing the top 15% of gemstone-quality diamonds, Very Good cut diamonds offer excellent value while maintaining impressive sparkle.

**Excellent**: The pinnacle of diamond cutting, Excellent cut diamonds are precisely crafted to unleash maximum brilliance and sparkle, with little to no light leakage. This premium grade represents the top 3% of all diamonds, and advancements in technology are increasing their availability. An Excellent cut diamond is always a top choice, regardless of shape and size.

Cut is often considered the most important of the 4 C's because it directly influences a diamond's sparkle and overall visual beauty. While Carat may be a preference, Cut is an art and science. To ensure you get a diamond that retains maximum light and sparkle, prioritize Excellent or Very Good cuts. The differences in sparkle, though subtle, are noticeable when compared side by side. Maximizing the Cut grade, if possible, will enhance the overall brilliance of your lab grown diamond engagement ring.

Color: Diamond's Shade or Tint

For lab grown diamond engagement rings, color refers to the subtle tint or shade of yellow or brown visible within the diamond. All diamonds on the GIA D through Z scale are considered white, though those at the lower end may display a faint yellow tint. This natural element affects a diamond's sparkle since increased yellow or brown tint reduces light reflection and performance, acting as a visual distraction. The color grade represents the visibility of this tint, with grading done by assessing the diamond's body color on a pure white background, face down. When viewed face up, the color is less noticeable. Understanding the color grade helps in choosing a diamond with optimal brilliance and minimal visual distraction.

diamond color guide chart

Clarity: The Diamond's Unique Imperfections

For lab grown diamond engagement rings, clarity refers to the presence of microscopic impurities or imperfections, known as inclusions, that form during the diamond growth process. These inclusions are common and give each diamond its unique character. Clarity is graded by gemologists on a scale from FL (Flawless) to I3 (Included) and is determined by examining the diamond under 10x magnification.

Clarity is the third most important characteristic among the 4 C's because most imperfections are not visible to the naked eye. To maximize your budget, consider an SI (Slightly Included) quality diamond, which may have very slight inclusions visible only upon close inspection.

Beyond the 4C's

While shopping for diamonds, it’s easy to focus on the big four: Cut, Color, Clarity, and Carat. However, understanding additional factors like symmetry, polish, and depth can further guide your decision. Symmetry evaluates how precisely the diamond's facets align, impacting its brilliance. Good symmetry ensures that light reflects correctly, enhancing the diamond's sparkle. 

Polish, the final finishing step, affects the diamond's surface smoothness. High-quality polish increases the stone's brilliance and overall appearance. Depth, measured from the culet to the table, influences the diamond's sparkle and proportions. The right depth percentage enhances the diamond's beauty, while poor depth can affect its visual appeal.

Additionally, diamond fluorescence, a glow seen under UV light, is a notable characteristic. About 30% of diamonds exhibit some fluorescence, graded from None to Very Strong. While fluorescence can affect a diamond's value, it is not inherently good or bad—it depends on personal preference.

Understanding these factors alongside the 4 C's will help you make an informed decision when choosing the perfect lab grown diamond engagement ring.


Do sapphires hold their value over time?

Yes, sapphires do hold their value over time; just ensure to opt for a high-quality grade natural sapphire with an intense hue.

What is the value of a lab created sapphire?

A lab created sapphire will sell for a lower price compared to a natural sapphire, and usually costs approximately $40 per carat.