Excellent and Very Good are the two highest cut grades on the standard GIA and IGI cut-grading scale, and the difference between them comes down to how precisely a diamond's proportions, symmetry, and polish align with the ranges known to maximize light return. An Excellent-cut stone sits at the very top of that range; a Very Good-cut stone falls just outside it, with a difference in light performance that's frequently difficult for even a trained eye to detect face-up, despite a real, sometimes meaningful price gap between the two grades.
This guide covers exactly what separates Excellent from Very Good cut, how the two grades compare on light performance, price, and proportions, when the difference actually matters, and how to decide which grade makes more sense for a given budget and stone size.
What "Cut Grade" Actually Measures
Cut grade evaluates how well a diamond's proportions, symmetry, and polish work together to maximize brilliance (white light return), fire (light dispersed into spectral colors), and scintillation (the sparkle pattern visible as the stone or viewer moves). It is a distinct measurement from the diamond's shape — cut grade specifically describes how well a stone of a given shape was proportioned and finished, not which shape it is. GIA and IGI both grade cut on a five-tier scale: Excellent, Very Good, Good, Fair, and Poor, based on a combination of measured proportions (table percentage, depth percentage, crown and pavilion angles) and observed finish (symmetry and polish).
Excellent Cut: What It Requires
An Excellent cut grade requires a diamond's proportions to fall within the tightest, most precisely calculated range for maximizing light return for its shape, combined with Excellent symmetry and polish. For a round brilliant specifically, this generally means a table percentage and depth percentage within a narrow optimal band, crown and pavilion angles calculated to work together for maximum light return, and facets cut and aligned with minimal deviation. Very few stones achieve this top tier, since it requires precision at every stage of the cutting process rather than strong performance in most areas with one or two proportions slightly outside the ideal range.
Very Good Cut: What It Requires
A Very Good cut grade sits just below Excellent — proportions fall slightly outside the tightest optimal range, or symmetry and polish are graded Very Good rather than Excellent, but the overall combination still delivers strong light performance. A Very Good-cut stone reflects the vast majority of light entering it and displays strong brilliance and fire, just not at the absolute maximum a stone of that shape and size is capable of. In practice, many gemologists and buyers consider Very Good the more efficient value tier, since it captures the large majority of an Excellent-cut stone's visual performance at a meaningfully lower price.
Excellent vs. Very Good Cut: Side-by-Side Comparison
| Factor | Excellent Cut | Very Good Cut |
|---|---|---|
| Light performance (brilliance, fire, scintillation) | Maximum for the shape | Strong, close to maximum — the practical difference is often not visible face-up |
| Proportions | Fall within the tightest optimal range | Fall just outside the tightest range, still within a strong performance window |
| Symmetry and polish | Excellent on both | Very Good on one or both, or proportions are the limiting factor instead |
| Relative price | Highest, all else equal | Meaningfully lower for a visually similar result |
| Availability | Less common — a smaller share of cut rough achieves this grade | More widely available across most shapes and sizes |
| Best for | Buyers prioritizing certificate-grade maximum performance and prestige | Value-focused buyers wanting strong performance without paying the top-tier premium |
Does the Difference Show Up to the Naked Eye?
For the large majority of buyers, the visual difference between an Excellent and a Very Good cut diamond of the same shape, size, color, and clarity is difficult or impossible to detect without side-by-side comparison under controlled lighting, and often even then. Both grades reflect the overwhelming majority of light entering the stone and display strong brilliance and fire in normal viewing conditions — the distinction that separates them is a matter of degree at the very top of the performance scale, not a visible difference between a sparkling stone and a dull one. Buyers expecting a dramatic visual gap between the two grades are typically surprised by how similar they actually look in person.
Which Shapes Actually Receive a GIA Cut Grade
It's worth noting that GIA's numeric cut grade (Excellent through Poor) applies specifically to round brilliant diamonds, since the round brilliant's proportions and light-performance modeling are well enough understood to support a standardized grading scale. Fancy shapes — oval, cushion, pear, emerald, and others — receive symmetry and polish grades on GIA reports, but not the same overall numeric cut grade a round brilliant does, since fancy shape proportions vary more by design intent and don't reduce to a single standardized optimal range the way round brilliant does. IGI does grade cut on several popular fancy shapes in addition to round. Buyers comparing "Excellent vs. Very Good" outside of round brilliant should confirm exactly which grading system and shape-specific standard a given certificate is using.
Price Difference Between Excellent and Very Good Cut
The price gap between Excellent and Very Good cut, holding shape, carat, color, and clarity constant, is real but generally smaller than the price gap driven by moving up a full color or clarity grade. Because Excellent-cut stones are less common — a smaller share of cut rough achieves the tightest proportion range — they carry a real premium, but many buyers find that premium is better spent moving up a color or clarity tier instead, since those differences are sometimes more visually apparent than the cut difference at this level.
When Excellent Cut Is Worth the Premium
- Larger center stones. At larger carat weights, where overall stone value is higher and light-performance differences can be marginally easier to notice under close inspection, some buyers prioritize the top cut tier specifically.
- Investment-grade or resale-focused purchases. A stone graded Excellent across cut, color, and clarity commands the strongest resale and appraisal positioning, relevant for buyers prioritizing that consideration specifically.
- Buyers who want certificate-grade maximum performance regardless of visible difference. Some buyers simply want the top grade on paper, independent of whether the visual difference is perceptible — a legitimate preference worth respecting even when the visual case for it is thin.
When Very Good Cut Is the Smarter Choice
- Budget-conscious buyers wanting strong performance. Very Good delivers the large majority of Excellent's visual performance at a meaningfully lower price, freeing up budget to spend on color, clarity, or carat weight instead.
- Buyers prioritizing overall stone size or grade combination. Reallocating the price difference from cut into a larger stone or better color/clarity grade often produces a more noticeable overall improvement than the cut upgrade alone would.
- Fancy shapes without a numeric cut grade. Since many fancy shapes don't receive the same Excellent/Very Good distinction as round brilliant, the practical decision for those shapes often comes down more to symmetry, polish, and visual inspection than chasing a specific cut-grade label.
How to Evaluate Cut Beyond the Certificate Grade
A cut grade on a certificate is a strong starting signal, but it doesn't fully capture how an individual stone performs, since two stones with the same grade can still look subtly different due to factors the standard grading scale doesn't fully capture — the specific balance between brilliance and fire, or how a stone performs under different lighting conditions. Requesting a video of the actual stone under multiple lighting conditions, rather than relying on the certificate grade alone, gives a buyer a more complete picture than the grade by itself, particularly when comparing two stones at the Excellent/Very Good boundary specifically.
Cut Grade for Lab-Grown vs. Natural Diamonds
Cut grading standards and scales apply identically to lab-grown and natural diamonds, since CVD lab-grown stones are chemically, physically, and optically identical to natural diamonds and are cut using the same proportions and standards. The Excellent vs. Very Good distinction, and the practical guidance on when each makes sense, applies the same way regardless of whether the stone is natural or CVD lab-grown.
Common Misconceptions About Cut Grade
- "Cut grade and diamond shape are the same thing." They're distinct — shape describes the outline (round, oval, cushion, and so on), while cut grade describes how well a stone of that shape was proportioned and finished.
- "A higher cut grade always means a more sparkly stone to the naked eye." Not necessarily — the difference between Excellent and Very Good is frequently not visible without close, side-by-side comparison, despite the real difference in graded proportions.
- "All shapes get the same cut grade scale as round brilliant." Only round brilliant receives GIA's full numeric Excellent-to-Poor cut grade; most fancy shapes are evaluated primarily on symmetry and polish instead.
- "A Very Good cut is a compromise, not a real choice." Many gemologists consider Very Good the more efficient value tier specifically because it captures most of Excellent's visual performance at a real price discount.
Practical Buying Recommendations
- Set a minimum cut floor, not necessarily a ceiling. Most buyers are well served by treating Very Good as an acceptable minimum and Excellent as a nice-to-have rather than a requirement, then allocating remaining budget to color, clarity, or carat weight.
- Always check symmetry and polish alongside overall cut grade. A stone can carry a strong overall cut grade while having a specific symmetry or polish note worth reviewing on the actual certificate rather than the summary grade alone.
- Request video or in-person review for a final decision at the Excellent/Very Good boundary. Since the visual difference is often marginal, direct observation is more useful than the certificate grade alone when deciding between two specific stones.
- Confirm which grading system and shape standard applies. For fancy shapes especially, understand whether "cut grade" on a given certificate means the same thing it does for a round brilliant.
Sourcing Excellent and Very Good Cut Diamonds at Wholesale
Guru Diam is a trade-only wholesale diamond supplier with locations in New York and Los Angeles, carrying CVD lab-grown and natural diamonds across every standard, antique, and exotic shape, with IGI, GIA, and GCAL certification available. Buyers can source stones at both Excellent and Very Good cut grades depending on budget and performance priorities, with full grading documentation on every certified stone.
Buyers can browse certified inventory through the certified diamonds category, source calibrated accent stones through matching pairs, or build a custom piece through custom jewelry. Trade accounts can review terms at the wholesale hub or apply through trade partner.
Understanding the Proportions Behind Cut Grade
Cut grade is calculated from a combination of specific measurements, each contributing to the overall grade rather than any single number determining it alone:
| Proportion | What It Measures | Why It Matters |
|---|---|---|
| Table percentage | The width of the flat top facet relative to the stone's total diameter | Affects how much light enters directly versus through the crown facets, influencing the balance of brilliance and fire |
| Depth percentage | The stone's total depth relative to its diameter | Too shallow or too deep and light escapes through the pavilion instead of reflecting back to the viewer |
| Crown angle | The angle of the facets above the girdle | Works together with pavilion angle to determine the balance between fire and brilliance |
| Pavilion angle | The angle of the facets below the girdle | The single most critical angle for determining whether light reflects back through the crown or leaks out the bottom |
| Girdle thickness | How thick or thin the stone's outer edge is | Affects durability and can influence total carat weight without adding visible size |
An Excellent grade requires this entire combination to fall within the tightest calculated range simultaneously — a stone can have excellent crown and pavilion angles but lose points elsewhere in the combination, landing it at Very Good rather than Excellent overall. This is part of why two Excellent-graded stones from different labs or different specific proportion combinations within the Excellent range can still look subtly different from one another, despite sharing the identical top grade.
How Symmetry and Polish Factor Into the Overall Cut Grade
Beyond proportions, symmetry (how precisely facets align and match each other) and polish (the smoothness of each facet's surface finish) are graded separately and factor into the overall cut grade. A stone with excellent proportions but only Very Good symmetry or polish can still receive an overall Very Good cut grade rather than Excellent, since the finishing quality genuinely affects how cleanly light reflects through the stone regardless of how well the underlying proportions were calculated. Poor symmetry can create doubling or blurring in the light pattern a trained eye can sometimes detect under magnification, while poor polish can leave microscopic surface irregularities that scatter light less efficiently than a properly polished facet. Buyers evaluating a certificate closely should check symmetry and polish as their own line items rather than assuming a strong overall cut grade means both were automatically graded at the top tier.
How Different Grading Labs Approach Cut Grade
GIA and IGI both use a five-tier Excellent-to-Poor cut grading scale for round brilliants, and their grading criteria are broadly similar, though buyers sourcing across multiple labs should be aware that minor methodological differences exist between grading organizations. A stone graded Excellent by one major lab would, in the vast majority of cases, also grade at the top tier from another major lab, since both are working from similar underlying light-performance research, but buyers making fine-grained comparisons across certificates from different labs should avoid assuming perfect interchangeability at the margins between adjacent grades. For most practical wholesale purposes, comparing cut grade only across certificates from the same lab, or treating a one-tier difference between labs as within normal variance rather than a meaningful signal, is the more reliable approach.
Cut Grade's Interaction With Overall Stone Value
While this guide focuses specifically on the Excellent-versus-Very-Good distinction, it's worth situating cut within the full pricing picture: of the 4Cs, cut is generally considered to have the largest single effect on a diamond's visual appeal, since even a diamond with excellent color and clarity can look visually unimpressive if poorly cut, while a well-cut stone with slightly lower color or clarity can still present beautifully. This is precisely why the Excellent-versus-Very-Good decision matters as one input within a broader budget allocation decision rather than in isolation — a buyer's total budget is generally better spent finding the right overall balance across all 4Cs than maximizing any single factor, including cut, at the expense of the others.
Super Ideal and Other Marketing Terms Above Excellent
Some retailers and cutters market a narrower subset within the Excellent range under terms like "Super Ideal," "Hearts and Arrows," or similar branded labels, referring to stones whose proportions and symmetry fall within an even tighter band than the standard Excellent threshold requires, often verified through additional light-performance imaging beyond the standard certificate. These aren't official grades issued by GIA or IGI — they're proprietary marketing terms layered on top of an underlying Excellent grade, and buyers encountering them should understand they represent a retailer or cutter's own additional quality claim rather than a distinct tier recognized by the major grading labs. Whether the added cost for this narrower subset is worthwhile follows the same logic as the broader Excellent-versus-Very-Good decision: the visual difference from a standard Excellent-grade stone is typically even more marginal than the Excellent-versus-Very-Good gap itself, making it a preference for buyers specifically chasing the most rigorous available cut classification rather than a broadly recommended upgrade.
How Wholesale Buyers Should Stock Across Cut Grades
A jeweler or designer building recurring wholesale inventory benefits from stocking across both Excellent and Very Good cut tiers rather than committing exclusively to one, since customer priorities vary enough across a typical customer base that both tiers see real, ongoing demand. Very Good inventory serves the larger share of value-conscious customers well, while maintaining some Excellent-grade inventory serves customers specifically seeking top-tier certification or planning a larger, more significant purchase where the premium is a smaller share of total spend. Framing the choice for retail customers as a genuine tradeoff — meaningfully lower price against a difference that's rarely visible without close comparison — rather than presenting Very Good as an inferior compromise, tends to produce more satisfied customers across both price points.
Frequently Asked Questions
What is the real difference between Excellent and Very Good cut diamonds?
Excellent requires proportions, symmetry, and polish to fall within the tightest range known to maximize light performance; Very Good falls just outside that range but still delivers strong brilliance and fire. The difference is often difficult to see face-up without close comparison.
Is an Excellent cut diamond worth the extra cost?
For many buyers, no — Very Good captures most of Excellent's visual performance at a meaningfully lower price, and that price difference is often better spent on color, clarity, or carat weight. Excellent is worth it for buyers specifically prioritizing top-tier certificate grading or resale positioning.
Do all diamond shapes receive an Excellent vs. Very Good cut grade?
No — GIA's full numeric cut grade applies specifically to round brilliant diamonds. Fancy shapes typically receive symmetry and polish grades instead, without the same standardized overall cut grade round brilliant gets.
Can you tell the difference between Excellent and Very Good cut just by looking?
Usually not without side-by-side comparison under controlled lighting, and often not even then. Both grades reflect the large majority of light entering the stone and appear bright and lively in normal viewing conditions.
Does cut grade matter more than color or clarity?
Many gemologists consider cut the most important of the 4Cs for overall visual appeal, since it determines how much of a diamond's potential brilliance and fire is actually realized. That said, the specific Excellent-vs-Very-Good distinction is a smaller factor than moving a full color or clarity grade.
Is Very Good cut the same as an "ideal" cut?
Not exactly — "ideal cut" is typically used as a marketing term for the top of the cut-grade range, roughly corresponding to Excellent, or in some cases an even narrower super-ideal subset within Excellent. Very Good sits one tier below that top range.
