How to Read an IGI Certificate in 2026: Full Report vs Card Certificate vs No-Plot Report
IGI reshaped how its lab-grown diamond reports are built. The clarity plot is now an add-on. The Hearts & Arrows notation is now an add-on. Two IGI reports for two identical stones can look completely different — and neither one is fake. This 2026 guide shows you how to read whichever version you have been handed, and how to work out whether you actually need the fuller one.
If you have compared two IGI certificates recently and found that one has an inclusion map and the other does not, nothing has gone wrong. Since 2026, several elements that buyers assumed were standard on an IGI report — the clarity characteristics plot and the Hearts & Arrows notation — are optional paid add-ons that the seller chooses, not automatic entries. None of this changes the grades themselves: a D/VVS2 stone is a D/VVS2 stone whether or not its plot is printed. What it does change is how much you can see for yourself. This guide walks through every current IGI format, explains which one is the industry norm at each carat band, and gives you a two-minute verification routine that works on all of them. Every diamond at MadisonDia ships with a full IGI report on stones of 1 carat and above.
What Changed on the IGI Certificate in 2026
For years, buyers learned one simple rule: a "proper" IGI report has a clarity plot, a proportions diagram, cut, polish and symmetry grades, and a comments line. Anything shorter was treated as a downgrade. That rule no longer describes the market accurately.
IGI has moved to a modular reporting structure. The grading itself is unchanged — the same gemologists, the same 10× clarity assessment, the same D-to-Z colour scale, the same cut grading methodology. What has changed is that several presentation elements of the report are now services the submitting seller elects and pays for, rather than items included by default.
Now an Optional Add-On: The Clarity Characteristics Plot
The inclusion map — the diagram showing where each characteristic sits inside your specific stone — is no longer printed on every lab-grown report. IGI's own documentation now describes reports as ones which "may also include" a diagram of clarity characteristics. The clarity grade is still assessed and printed either way.
Now an Optional Add-On: Hearts & Arrows Notation
A stone can be a genuine Hearts & Arrows cut and have a report that never says so, because IGI only records it when the seller requests and pays for it. The cut, polish and symmetry grades are identical either way. Absence of an H&A note is not evidence the stone lacks the pattern.
Unchanged: The Grades Themselves
Shape and cutting style, measurements, carat weight, colour, clarity, and the report number appear on every current IGI format. On full reports, cut, polish, symmetry and proportion percentages appear as well. These are the numbers that determine what you are paying for.
Unchanged: The Laser Inscription
Every lab-grown diamond IGI reports on carries the prefix LG laser-inscribed on the girdle ahead of the report number, and noted in the comments. This is the anchor that ties the paper to the physical stone, and it survives every format change.
✓ The Short Version, If You Read Nothing Else
Grading labs revise their formats periodically; IGI has done so several times over the decades. A newer, leaner-looking report is not a lesser diamond. If the report number resolves on igi.org and the LG-prefixed number is inscribed on the girdle of the stone in front of you, your paperwork is sound. The only real question left is whether the format you have gives you enough visibility for the size and price of stone you are buying — which is what the rest of this guide is about.
The Four IGI Certificate Versions You Will Meet in 2026
Because the add-ons are elected stone by stone, several formats now circulate side by side. Here is the practical landscape, from most information to least:
| Format | What It Contains | Typical Carat Band | How Common in 2026 |
|---|---|---|---|
| Full report + cut notation | Everything below, plus Hearts & Arrows or light-performance notation as an elected add-on | 2.0ct and above | Industry standard at this size |
| Full report with clarity plot | 4Cs, cut/polish/symmetry, fluorescence, full proportion percentages, growth method, comments, inclusion map | 1.0ct – 2.0ct | The mainstream format overall |
| Full report, no clarity plot | 4Cs, cut/polish/symmetry, fluorescence, full proportion percentages, growth method, comments — but no inclusion map | Below 1.0ct, increasingly | The newest and fastest-growing format |
| Card certificate | Shape, carat, a colour range (e.g. D–E), a clarity range (e.g. VS–VVS), the description "Laboratory Grown", report number | Small stones, melee parcels, set jewellery | Uncommon in single-stone retail |
⚠️ The Distinction Most Buyers Get Wrong
"Full report without a clarity plot" and "card certificate" are not the same thing, and the gap between them is enormous. A full report without a plot still gives you the exact colour grade, the exact clarity grade, the cut grade, and every proportion percentage — you simply cannot see where the inclusions sit. A card certificate gives you a range rather than a grade, and no cut data at all. If a seller describes a stone as "IGI certified" and hands you a range, you are missing considerably more than a diagram.
How to Read an IGI Full Report, Line by Line
Work down the report in this order. Each field answers a specific question about your stone.
Report Number & Description
The description reads "Laboratory Grown Diamond" plainly — IGI does not obscure origin. The report number is your verification key and is also inscribed on the girdle with the LG prefix. Note it before you do anything else.
Shape & Cutting Style
For example "Round Brilliant", "Oval Brilliant", "Cushion Modified Brilliant". This matters more than it looks: cut grading is calculated differently for round brilliants than for fancy shapes, so the shape line tells you how to interpret the grades beneath it.
Measurements & Carat Weight
Millimetre dimensions and exact weight to two decimals. Two 1.00ct rounds can differ by 0.3mm in diameter — the one that spreads wider will look bigger face-up. Compare measurements, not just carat, when you are choosing between stones.
Colour & Clarity Grades
A single letter and a single clarity grade — not a range. Colour is assessed with the stone face-down under controlled light by multiple independent graders; clarity is assessed at 10× magnification. These two lines carry most of the price.
Cut, Polish & Symmetry
The craftsmanship trio. On a round brilliant, Excellent across all three ("3EX") is the benchmark. Cut is the single largest driver of visible sparkle, and it is the field a card certificate omits entirely.
Proportions: Table %, Depth %, Angles
Table percentage, depth percentage, crown angle, pavilion angle, girdle thickness and culet. This block is present even on reports without a clarity plot, and it lets you assess light performance numerically. See the recommended ranges below.
Fluorescence & Growth Method
Fluorescence records any glow under UV. Growth method identifies CVD or HPHT. Both are legitimate production routes, but the distinction matters for certain jewellery formats — on a pavé line, for instance, HPHT stones can show uneven phosphorescence.
Comments
Watch for "No indication of post-growth treatment". Some lab-grown diamonds are HPHT-treated after growth to lift colour, which visual inspection cannot detect. IGI notes any permanent treatment here, and will not issue a full grading report for non-permanent treatments.
The IGI Report Without a Clarity Plot: Who It Suits
This is the newest format and the one causing the most confusion, so it deserves a straight explanation. You receive a complete grading report — every grade, every proportion percentage, growth method, comments — but the page where you would expect the inclusion map either carries a proportions diagram alone or leaves the space out.
What You Lose Without the Plot — and When That Actually Matters
The plot answers one question the grade alone cannot: where are the characteristics, and are they somewhere that shows? Two stones can both grade VS1, but one has its inclusion tucked under a crown facet near the girdle, and the other has it sitting directly under the table. Same grade, different stone. The plot is how you tell them apart without a loupe in your hand.
How much that matters depends almost entirely on size. On a 0.30ct or 0.50ct stone, characteristics at VS or better are physically too small to resolve with the naked eye no matter where they sit — the plot would confirm something you could never see anyway. From roughly 1 carat upward, the facets are large enough that placement starts to have visible consequences, and the plot becomes a genuine decision tool. At 2 carats and above, we would not buy without one.
✓ A Reasonable Rule of Thumb
Under 1 carat: a full report without a clarity plot is perfectly sensible, and paying extra for the diagram buys you reassurance rather than information. 1 carat and above: ask for the plot. At this size it is how you separate a stone that is eye-clean from one that merely grades eye-clean, and it costs you nothing to request it from a seller who already holds the report.
The IGI Card Certificate: Still Real, Rarely Used
The card certificate still exists and is still an authentic IGI document. It is simply built for a different job: verifying small stones, melee parcels, and diamonds already set into finished jewellery, where individually grading each stone would be impractical.
| Field | IGI Full Report | Full Report (No Plot) | IGI Card Certificate |
|---|---|---|---|
| Report number & LG inscription | ✔ | ✔ | ✔ |
| Description "Laboratory Grown" | ✔ | ✔ | ✔ |
| Shape & cutting style | ✔ | ✔ | ✔ |
| Carat weight | ✔ | ✔ | ✔ |
| Colour | Exact grade | Exact grade | Range only (e.g. D–E) |
| Clarity | Exact grade | Exact grade | Range only (e.g. VS–VVS) |
| Measurements | ✔ | ✔ | ✘ |
| Cut grade | ✔ | ✔ | ✘ |
| Polish & symmetry | ✔ | ✔ | ✘ |
| Proportions (table %, depth %, angles) | ✔ | ✔ | ✘ |
| Fluorescence | ✔ | ✔ | ✘ |
| Growth method (CVD / HPHT) | ✔ | ✔ | ✘ |
| Comments (post-growth treatment) | ✔ | ✔ | ✘ |
| Clarity characteristics plot | ✔ | ✘ | ✘ |
| Hearts & Arrows notation | Optional add-on | Optional add-on | ✘ |
⛔ Where the Card Format Becomes a Problem
A card certificate is appropriate for a pavé line or an accent stone. It is not appropriate for a centre stone you are paying a centre-stone price for. The reason is structural: because the card records a colour and clarity range and omits cut entirely, a stone at the bottom of every range with a mediocre cut and a stone at the top with an Excellent cut can carry the same card. If a seller offers a solitaire above 0.50ct on a card certificate only, ask why the full report was not issued — and treat a vague answer as your answer.
Hearts & Arrows on an IGI Certificate Is Now a Paid Add-On
Hearts & Arrows describes a cut executed with enough precision that the facet reflections overlap into a pattern of eight hearts viewed face-down and eight arrows face-up. IGI publishes a dedicated Hearts & Arrows report and describes the precision as typically associated with Excellent-Ideal cuts of superior quality.
The commercially important point for 2026 buyers: IGI does not record the pattern automatically. The notation is elected and paid for by the seller. This produces three consequences worth internalising:
1. Silence Is Not Evidence
A report with no H&A mention tells you nothing about whether the stone has the pattern. Plenty of true Hearts & Arrows stones circulate on standard reports because the seller declined a paid line item that would not change a single grade.
2. The Grades Are Unaffected
Adding H&A notation does not raise the cut, polish or symmetry grade. A 3EX stone is 3EX with or without it. The add-on documents a pattern; it does not upgrade anything.
3. There Is a Carat Convention
Below roughly 2 carats, most sellers skip the paid notation and demonstrate the pattern with photographs or a scope video instead. From around 2.5 carats upward, the notation is commonly added — at that value it is worth the fee.
4. Weak H&A Is Worse Than Good Traditional
The pattern only means something on a precisely cut stone. Hearts & Arrows below IGI Ideal / 3EX can look worse than a well-cut traditional stone at the same grade. Never treat H&A as a substitute for the cut grade.
⚠️ How to Handle This as a Buyer
If Hearts & Arrows matters to you, do not shop for the words on the certificate — ask the seller for scope imagery or video of the actual stone, and confirm the cut, polish and symmetry are Excellent/Ideal on the report. That combination tells you more than a paid notation ever will. If you want the notation specifically for resale documentation on a larger stone, ask before the report is issued; adding it afterwards means resubmission.
The 4Cs Charts and Recommended Proportions for Lab-Grown Diamonds
These scales have not changed and appear on every full report. Use them alongside the proportion percentages, which are present even on reports without a clarity plot.
Diamond Colour Scale
| Grade | Description | Practical Note |
|---|---|---|
| D – F | Colourless | Reads fully white in any metal, including platinum and white gold |
| G – J | Near colourless | Warmth becomes visible against white metal at larger sizes |
| K – M | Faint colour | Visible tint face-up; suits yellow gold settings only |
| N – R | Very light colour | Rarely offered in lab-grown retail |
| S – Z | Light colour | Rarely offered in lab-grown retail |
Diamond Clarity Scale
| Grade | Description | Practical Note |
|---|---|---|
| FL – IF | Flawless / Internally Flawless | A price premium with no visible benefit at any size |
| VVS1 – VVS2 | Very, very slightly included | Reliably eye-clean; the sensible target for a centre stone |
| VS1 – VS2 | Very slightly included | Usually eye-clean, but placement matters — this is where the plot earns its keep |
| SI1 – SI2 | Slightly included | Inclusions can be visible face-up at 1ct and above |
| I1 – I3 | Included | Visible characteristics; not recommended for centre stones |
Diamond Cut Grades
| Grade | What You See |
|---|---|
| Excellent / Ideal | Optimal brightness, fire and scintillation |
| Very Good | High brilliance with minor light leakage |
| Good | Noticeable variation in brilliance |
| Fair | Limited sparkle; light escapes through the pavilion |
| Poor | Dull; little return of light |
Recommended Proportions for Round Brilliant Diamonds
If your report has no clarity plot, this block is where you do your analysis. These ranges are what a well-performing round brilliant typically falls within:
| Parameter | Recommended Range | Why It Matters |
|---|---|---|
| Table % | 54% – 57% | Balances white light return against fire |
| Depth % | 61% – 62.5% | Too deep and the stone looks small; too shallow and light leaks |
| Crown angle | 34° – 35° | Governs dispersion — the coloured flashes |
| Pavilion angle | 40.6° – 41° | The single most sensitive proportion for light return |
| Girdle thickness | Thin – Medium | Extremely thin risks chipping; very thick hides weight |
| Culet | None – Very Small | A large culet shows as a dark spot through the table |
Carat Weight
Carat measures weight, not size as seen. A well-cut 1.00ct round can look larger and livelier than a poorly cut 1.20ct, because proportion determines both face-up spread and light return. This is precisely why the omission of cut data on a card certificate is more serious than the omission of a clarity plot on a full report.
Which IGI Certificate Do You Actually Need? A Guide by Carat Size
Rather than insisting on the maximum documentation for every purchase, match the format to the stone. Paying for a plot on a 0.30ct accent stone is spending money on paper; skipping one on a 2ct centre stone is a genuine risk.
| Stone Size | Minimum You Should Insist On | Clarity Plot? | H&A Notation? |
|---|---|---|---|
| Melee / pavé (under 0.10ct) | Seller's stated colour and clarity range | Not applicable | Not applicable |
| 0.10 – 0.50ct accent or small solitaire | Full report (plot not required) | Optional — nothing is eye-visible at this size | No |
| 0.50 – 1.00ct | Full report with cut, polish, symmetry | Useful; ask if it exists | No — request scope imagery instead |
| 1.00 – 2.00ct centre stone | Full report, 3EX or Ideal cut | Yes — request it | Optional; imagery is usually sufficient |
| 2.00ct and above | Full report, 3EX or Ideal cut | Yes — non-negotiable | Industry standard at this size |
How to Verify Any IGI Certificate in Two Minutes
This routine works identically on a full report, a report without a plot, and a card certificate. Do it before payment, not after.
The Four-Step Verification Routine
- Read the girdle inscription. Under a 10× loupe, find the laser inscription on the girdle. It should begin with LG followed by the report number. This is the link between the paper and the physical stone.
- Enter the number at igi.org. Use the official IGI report verification page. The digital record should appear and match the printed document.
- Compare every field. Carat, colour, clarity, measurements, cut, polish, symmetry. Any discrepancy between the printed report and the online record — even a decimal — is a stop signal.
- Check the comments line. Confirm there is no indication of post-growth treatment, and note the growth method. If the comments mention a treatment you were not told about, that is a pricing conversation.
IGI also documents the report layout field by field on its own guide to reading a lab-grown diamond report, which is worth ten minutes if you want to trace every line yourself.
IGI Certificate Red Flags That Genuinely Matter
Now that formats vary legitimately, it is worth separating the things that are simply different from the things that are actually wrong.
✓ Not a Red Flag
- No clarity characteristics plot on a sub-1ct stone — the current standard format.
- No Hearts & Arrows notation — an unpurchased add-on, not a missing grade.
- A report layout that looks different from one you saw two years ago — IGI revises its formats periodically.
- The word "Laboratory Grown" printed prominently — that is IGI doing its job, not a downgrade.
⛔ Genuine Red Flags
- The report number does not resolve at igi.org, or resolves to different specifications than the printed copy.
- No laser inscription on the girdle, or an inscription that does not match the report number.
- A colour or clarity range presented as an exact grade — e.g. a seller quoting "D VVS" from a card that actually reads D–E, VS–VVS.
- A centre stone above 0.50ct offered on a card certificate only, with no explanation of why a full report was not issued.
- Refusal to let you photograph the report or record the number before payment.
- A "certificate" from a lab you cannot find independently online. Verify against a recognised body — for natural stones, the GIA Report Check serves the same purpose.
MadisonDia vs. Typical Market Practice: IGI Certification Compared
MadisonDia operates under Kardias Fashion Group Limited. Our parent, Madison Avenue, has been an authorised dealer for Versace, Hugo Boss and Moschino in Hong Kong since 2012, and the business has been certified under the Hong Kong Government's "No Fakes Pledge" since 2014. We hold a 5.0 rating on BUYMA across 1,343+ verified reviews. Below is how our certification practice compares with what buyers commonly encounter.
| Certification Practice | MadisonDia | Common Market Practice |
|---|---|---|
| Report format on 1ct+ centre stones | Full IGI report, always | Varies; card certificates still appear on centre stones |
| Clarity plot on 1ct+ | Requested as standard | Increasingly skipped to reduce certification cost |
| Grade disclosure | Exact colour and clarity grade quoted | Ranges sometimes quoted as if they were exact grades |
| Certificate timing | Every diamond of 1ct and above comes with its IGI certificate, emailed to you ahead of dispatch | Frequently supplied only on delivery, or on request |
| Quality floor | D colour / VVS clarity / 3EX cut on centre stones of 1ct and above | No stated floor; grade mix varies by stone |
| Melee and pavé stones | D–F colour, VS–VVS clarity, CVD-grown; no individual IGI report at melee size, stated plainly | Sometimes described as "IGI certified" without qualification |
| Additional optical assessment | Proprietary MISI™ Ideal Sparkle Index, minimum score of 80 to be listed | None beyond the report |
| Hearts & Arrows handling | Sourced only at Ideal/3EX; scope imagery supplied, notation added on request for larger stones | H&A claimed verbally without report support or imagery |
| Pre-purchase verification | Report number provided before payment for igi.org checking | Often withheld until the sale is complete |
| Loose stone returns | 30-day unconditional return, full refund, no fees | Frequently final sale, particularly on wholesale channels |
| Finished jewellery | 14-day conditional return plus 1-year complimentary repair | Varies widely; repair often chargeable |
| Where you can inspect | Walk-in shop in Tsim Sha Tsui, Hong Kong, plus online purchase | Online-only for most lab-grown specialists |
MadisonDia Certified Lab-Grown Diamonds & 2026 Pricing
All loose stone pricing below is for D colour, VVS2 clarity, 3EX cut, IGI certified round brilliants, with the certificate included.
| Carat | Specification | HKD | USD (approx.) |
|---|---|---|---|
| 1.0 ct | D / VVS2 / 3EX / IGI | HK$1,904 | ~US$250 |
| 1.5 ct | D / VVS2 / 3EX / IGI | HK$3,184 | ~US$417 |
| 2.0 ct | D / VVS2 / 3EX / IGI | HK$4,704 | ~US$617 |
| 2.5 ct | D / VVS2 / 3EX / IGI | HK$6,064 | ~US$795 |
| 3.0 ct | D / VVS2 / 3EX / IGI | HK$7,584 | ~US$994 |
Round Lab-Grown Diamonds
Our core loose stone selection, every stone of 1 carat and above graded by IGI at D colour and VVS clarity, with the report number available before you buy so you can verify it yourself.
Design Your Own Engagement Ring
Choose the certified centre stone first, then build the setting around it with CAD and 3D preview before production, and photo confirmation before dispatch.
MISI™ Ideal Sparkle Index
Our proprietary optical assessment, applied after IGI grading. It measures light return, scintillation and fire on a 0–100 scale; only stones scoring 80 or above are listed.
IGI vs GIA in 2026
If you are weighing which laboratory to buy against, this companion article compares grading discipline, cost, turnaround and resale perception between the two.
Every Diamond, Fully Documented Before You Pay
Full IGI report on stones of 1 carat and above ・ Report number shared before purchase ・ 30-day unconditional return on loose diamonds ・ 1-year complimentary repair on finished jewellery
View Certified Lab-Grown DiamondsFrequently Asked Questions About Reading an IGI Certificate
My IGI certificate has no clarity plot. Is it fake?
No. Since 2026 the clarity characteristics plot is an optional paid add-on rather than an automatic inclusion, and reports issued without one are now common — particularly below 1 carat. Every grade is still there: colour, clarity, cut, polish, symmetry, and the full proportion percentages. Verify the report number at igi.org and check the LG-prefixed laser inscription on the girdle. If both match, your certificate is genuine.
What is the difference between an IGI full report and an IGI card certificate?
A full report gives you exact colour and clarity grades plus cut, polish, symmetry, measurements, fluorescence, growth method, comments and full proportion data. A card certificate gives a colour range and a clarity range, the shape, carat weight, the description "Laboratory Grown", and the report number — with no cut grade at all. Because cut is the largest driver of visible sparkle, the card format is suited to melee and set jewellery rather than centre stones.
Why does my certificate not say Hearts & Arrows even though the seller says it is?
IGI records Hearts & Arrows only when the submitting seller requests and pays for the notation. It is an add-on that does not change the cut, polish or symmetry grades, so many genuine H&A stones carry standard reports. Below roughly 2 carats most sellers skip it and demonstrate the pattern with scope imagery instead; from around 2.5 carats it is commonly added. Ask for photographs or video of the actual stone and confirm the cut grade is Excellent or Ideal.
Do I need a clarity plot on a diamond under 1 carat?
Generally no. The plot tells you where characteristics sit within the stone, but below 1 carat the facets are small enough that VS-or-better characteristics are not resolvable by eye regardless of placement. From 1 carat upward the plot becomes genuinely useful for confirming a stone is eye-clean rather than merely graded eye-clean, and at 2 carats and above we would treat it as essential.
Does a shorter IGI report mean a lower-quality diamond?
Not by itself. The grades are produced by the same process regardless of which presentation elements the seller elected. What a shorter report does mean is less visibility for you — so the shorter the report, the more you should rely on the seller's stated quality floor, on the ability to verify the number at igi.org, and on being able to see the stone or high-quality imagery of it before you commit.
What does "LG" on the girdle mean?
Every laboratory-grown diamond IGI issues a report for carries the prefix LG laser-inscribed on the girdle ahead of the report number, and noted in the report comments. It confirms the origin of the stone and links the physical diamond to its paperwork. Read it with a 10× loupe and check it against the report before payment — this is the single most effective protection against stone substitution.
What should the comments section say on a lab-grown diamond report?
Look for a note reading "No indication of post-growth treatment". Some lab-grown diamonds are HPHT-treated after growth to improve colour, which cannot be detected visually. IGI notes permanent treatments in the comments and does not issue full grading reports for stones with non-permanent treatments. The comments will also record the laser inscription.
Which proportions should I look for if my report has no clarity plot?
For a round brilliant, aim for a table of 54–57%, depth of 61–62.5%, a crown angle of 34–35°, a pavilion angle of 40.6–41°, thin-to-medium girdle and a culet of none-to-very-small. Pavilion angle is the most sensitive figure for light return. These percentages appear on every full report, so you can assess light performance numerically even without the inclusion map.
Does MadisonDia issue full IGI reports on every diamond?
Every centre stone of 1 carat and above comes with a full IGI report, and the certificate is emailed to you ahead of dispatch so you can verify it at igi.org. Melee and pavé stones under 1 carat are not individually IGI-certified — grading each stone at that size is not practical — so we state their specification directly instead: D–F colour, VS–VVS clarity, CVD-grown. We would rather tell you that plainly than describe a pavé line as "IGI certified".
Can I inspect a diamond and its certificate in person in Hong Kong?
Yes. Our shop is at G11, Hankow Centre, 5–15 Hankow Road, Tsim Sha Tsui, Hong Kong. You are welcome to walk in without an appointment to examine loose stones and read the reports alongside our team. Open daily 12:00–20:30, closed Saturdays. Note that G11 is on the shopping-mall ground floor, not the office tower. Learn more via our Brand Story.
Further Reading
- The Ultimate Lab-Grown Diamond Certification Guide: IGI vs GIA vs HRD
- IGI vs GIA in 2026: Which Certificate Should You Trust?
- 1 Carat Diamond Price in 2026: Natural vs Lab-Grown
- Lab-Grown Diamond Engagement Rings: The Complete Buying Guide
- MadisonDia Master FAQ
- MadisonDia's verified 5.0 BUYMA seller portfolio
