The cut of a diamond is the most critical factor in determining its brilliance, fire, and overall visual appeal. For lab-grown diamonds, cut grades such as “Ideal” and “Excellent” are used to describe the precision of the diamond’s proportions, polish, and symmetry. However, the distinction between these two terms can be confusing for buyers.
“Excellent” is the highest cut grade in the Gemological Institute of America’s (GIA) traditional grading system, while “Ideal” was originally coined by the American Gem Society Laboratories (AGSL) to represent its own highest standard of cut quality. Since the acquisition of AGSL by GIA in 2022, the term “Ideal” has been incorporated into the AGS Ideal Report, now issued by GIA. Understanding these terms and their implications is key to choosing a lab diamond with exceptional light performance.
Understanding Diamond Cut Grades
Diamond cut grades are an assessment of how well a diamond has been shaped and proportioned to interact with light. They evaluate factors like brilliance (white light reflection), fire (colored light dispersion), and scintillation (sparkle from movement).
Cut grades are typically categorized as follows:
- Excellent: The highest grade in the GIA’s original system, indicating a diamond that achieves exceptional brilliance and fire.
- Ideal: The top grade in the AGSL system (now under GIA as the AGS Ideal Report), representing a diamond with unparalleled precision in cut, polish, and symmetry.
The differences between these grades are subtle but can influence a diamond’s light performance. Both grades aim to maximize the diamond’s ability to reflect and refract light, but Ideal-cut diamonds may adhere to stricter standards depending on the certifying body.
GS Ideal vs. GIA Excellent Diamonds: A visual comparison of light performance and symmetry through diamond images, Ideal Scope, ASET, and Hearts imaging tools, illustrating the superior precision of AGS Ideal cuts.
For those seeking the absolute pinnacle of light performance, super-ideal cuts like Whiteflash Precision lab diamonds go above and beyond, offering unmatched brilliance and precision. If the pinnacle of quality isn’t within your budget, James Allen and Blue Nile offer great options at more affordable price points.
The Evolution of ‘Ideal’ and ‘Excellent’ Cut Grades
The distinction between “Ideal” and “Excellent” cut grades originates from two prominent diamond grading systems.
- The Term ‘Ideal’: The term “Ideal” was first introduced by the American Gem Society Laboratories (AGSL) in the 1990s. AGSL created its grading scale to emphasize the precision and balance required for exceptional light performance. A diamond graded as “AGS Ideal” (also known as AGS 0) represented the pinnacle of cut quality.
- The GIA Acquisition: In 2022, the Gemological Institute of America (GIA) acquired AGSL, integrating its expertise and grading methodologies. This acquisition led to the creation of the AGS Ideal Report, issued by GIA, which preserves the AGS grading scale. The AGS 0 Ideal designation continues to be recognized as a benchmark for excellence.
- ‘Excellent’ Cut Grades: The GIA developed its own cut grading system in 2005, with “Excellent” as the highest grade. While similar to the AGS Ideal, the GIA’s Excellent cut grade has historically been slightly broader in its criteria, offering consumers a range of high-performing diamonds.
Today, both grading systems coexist, with “Ideal” and “Excellent” used to denote exceptional cut quality. However, some diamonds, such as super-ideal cuts like Whiteflash’s Precision Lab diamonds, go beyond even these standards. These diamonds prioritize ultra-precise facet alignment and optical symmetry, delivering unmatched brilliance, fire, and scintillation.
Defining ‘Ideal’ and ‘Excellent’ Cut Grades
While both “Ideal” and “Excellent” cut grades represent exceptional craftsmanship, there are distinctions in their criteria and evaluation methods:
| Feature | Ideal (AGS 0) | Excellent (GIA) |
|---|---|---|
| Certifying Body | AGS (via GIA’s AGS Ideal Report) | GIA |
| Scope | Focuses on precision, optical symmetry, and light performance. | Evaluates brilliance, fire, and scintillation. |
| Stringency | Slightly stricter standards, especially for facet alignment and symmetry. | Broad but comprehensive criteria for overall light performance. |
| Optical Symmetry | Essential for receiving the AGS 0 grade. | Considered but not always mandatory. |
Both grades ensure diamonds with exceptional sparkle, but Ideal cuts, particularly those verified through AGS Ideal Reports, are known for tighter tolerances and a more rigorous evaluation process.
Buyers should also consider super-ideal cuts, which build upon these standards by achieving perfection in facet alignment and symmetry. Diamonds like Whiteflash Precision Lab exemplify this category, offering an unparalleled blend of technical precision and visual beauty. These diamonds are an excellent choice for those seeking the absolute best in cut quality. Other option include James Allen True Hearts.
Comparing Ideal and Excellent Cut Lab Diamonds
When choosing between Ideal and Excellent cut lab diamonds, the differences often come down to the level of precision and attention to detail in their cut. While both grades deliver exceptional sparkle, there are nuances to consider:
- Light Performance:
Both Ideal and Excellent cuts excel at reflecting light, maximizing brilliance and fire. However, Ideal cuts—particularly those graded as AGS 0—are often evaluated with stricter standards for facet alignment and optical symmetry. This can result in more consistent and dynamic light performance across a diamond’s surface. - Grading Criteria:
The AGS Ideal grading system is slightly more stringent, particularly regarding symmetry and proportions, as verified through the AGS Ideal Report. GIA’s Excellent cut grade is broader, allowing for a wider range of diamonds to qualify, which means the light performance can vary within this category. - Visual Impact:
Ideal cuts, especially those classified as super-ideal cuts, such as Whiteflash A Cut Above®, often demonstrate a superior balance of brilliance, fire, and scintillation. These diamonds are cut to near-perfection, creating a more noticeable sparkle compared to some Excellent cuts. - Price Differences:
Ideal cuts, due to their tighter tolerances and additional labor during cutting, may command a premium compared to Excellent cuts. However, the price difference can often be justified by the diamond’s enhanced optical performance and beauty.
Ultimately, while both grades represent high-quality diamonds, those seeking the absolute best in craftsmanship and performance may find Ideal cuts more appealing.
Choosing the Right Cut for Your Lab Diamond
Selecting between Ideal and Excellent cut lab diamonds depends on your priorities, preferences, and budget. Here’s how to make an informed choice:
- For Maximum Sparkle:
If unparalleled brilliance, fire, and scintillation are your top priorities, opt for an Ideal cut diamond, particularly one graded as AGS 0 or a super-ideal cut. These diamonds deliver the highest level of optical performance. - For a Balanced Approach:
If you want a diamond with excellent light performance but prefer a slightly more cost-effective option, a GIA Excellent cut diamond can provide great value while maintaining exceptional beauty. Be sure to review high-resolution images and light performance reports. - Review Certifications:
Look for AGS Ideal Reports (issued by GIA) or GIA Excellent cut grading to ensure your diamond meets high standards. Certifications from GCAL are also valuable for verifying precision and performance. - Inspect Visuals:
Always request HD images, videos, or advanced light performance imagery (like ASET or Idealscope) to understand how the diamond interacts with light. This is especially crucial when distinguishing between Ideal and Excellent cuts. - Work with Reputable Vendors:
Retailers like Whiteflash, James Allen, and Brilliant Earth offer a range of Ideal and Excellent cut lab diamonds with transparent grading and visual tools. Whiteflash’s A Cut Above®/Precision lab diamonds are particularly recommended for buyers seeking the finest craftsmanship.
Choosing the right cut comes down to understanding the nuances of these grades and aligning them with your expectations. Whether you choose Ideal or Excellent, prioritize cut quality to ensure your lab diamond offers the brilliance and beauty you desire.
Conclusion
When it comes to lab diamonds, the cut grade is the single most important factor in determining brilliance, fire, and overall sparkle. Both Ideal and Excellent cut diamonds represent exceptional quality, but understanding their differences can help you make the best choice for your needs.
Ideal cuts, particularly those graded as AGS 0 in the AGS Ideal Report from GIA, adhere to stricter standards, often delivering superior optical performance. For those seeking the absolute pinnacle of light performance, super-ideal cuts like Whiteflash Precision Lab diamonds go above and beyond, offering unmatched brilliance and precision. I would also consider the James Allen True Hearts lab diamonds.
On the other hand, Excellent cut diamonds, graded by GIA, provide outstanding value and beauty but may vary slightly in precision. When selecting either grade, focus on certifications, review HD visuals, and prioritize trusted retailers to ensure your diamond meets your expectations.
Ultimately, whether you choose an Ideal or Excellent cut, investing in a well-cut lab diamond guarantees a stunning piece that will captivate with its sparkle and beauty for years to come.
