Understanding Diamond Grading: Natural vs. Lab-Grown Diamonds

What is Diamond Grading?

Diamond grading is the expert process of evaluating a diamond’s quality and value based on four main characteristics called the 4Cs: Cut, Color, Clarity, and Carat weight. These factors help determine how beautiful and valuable a diamond is.

Natural vs. Lab-Grown Diamonds: What’s the Difference?

  • Natural Diamonds form deep within the Earth over millions of years through natural geological processes.

  • Lab-Grown Diamonds are created in laboratories using advanced technology. They have the same physical, chemical, and optical properties as natural diamonds but are produced much faster.

Both types of diamonds can be certified and graded for quality.

Who Grades Diamonds?

The most trusted and widely recognized diamond grading labs include:

  • GIA (Gemological Institute of America): The global leader in diamond grading, known for strict standards. GIA grades natural diamonds and also grades lab-grown diamonds but has recently updated its grading approach soon for lab-grown diamonds.

  • IGI (International Gemological Institute): Very active in grading lab-grown diamonds, offering detailed reports.

  • GCAL (Gem Certification & Assurance Lab): Known for consumer-friendly lab-grown diamond certifications.

How Diamonds Are Graded: The 4Cs Explained

  • Cut: Measures how well the diamond’s facets interact with light to create sparkle and brilliance.

  • Color: Grades how colorless a diamond is, from D (colorless) to Z (light yellow or brown).

  • Clarity: Assesses the presence of internal or external flaws called inclusions or blemishes.

  • Carat Weight: The size or weight of the diamond.

Special Grading for Lab-Grown Diamonds

Lab-grown diamonds receive similar grading based on the 4Cs, but grading labs also use specialized tests to identify their lab origin. This ensures transparency and authenticity.

Important GIA Update on Lab-Grown Diamond Grading (Effective Late 2025)

Starting late 2025, the GIA will change how it grades lab-grown diamonds:

  • Instead of giving traditional detailed 4C grades (like “G color” or “VS2 clarity”), lab-grown diamonds will be classified into two simple quality tiers:

    • Premium

    • Standard

  • Lab-grown diamonds that do not meet minimum quality standards will receive no grade.

  • This new approach reflects the fact that over 95% of lab-grown diamonds fall within a narrow quality range, making the detailed 4Cs less meaningful for these stones.

  • The change will help buyers easily understand lab-grown diamond quality and clearly distinguish lab-grown from natural diamonds.

What This Means for You as a Buyer

  • Shopping for lab-grown diamonds will be simpler and more straightforward with clear quality categories.

  • Natural diamonds will continue to be graded with the full 4Cs scale, preserving their unique value and rarity.

  • All GIA-graded diamonds, whether natural or lab-grown, undergo rigorous testing to ensure authenticity and quality.

Have Questions? We’re Here to Help!

If you want to learn more about diamond grading or need guidance choosing the perfect diamond—natural or lab-grown—please contact us. Browse our certified diamond collections today and shop with confidence.