- IGI-certified diamonds
- Triple Excellent standard
- Lifetime setting upgrades
- Free, fully insured shipping
- Made to order in Toronto
A diamond certificate — properly a grading report — is an independent laboratory's assessment of your stone's 4Cs, measurements and identity. It is your proof of exactly what you are buying. Here is how to read every section, how a lab-grown report differs, and how to verify it is genuine.
Key takeaways
- A report grades the 4Cs plus measurements, fluorescence and an ID number.
- It is not an appraisal — it states quality, not dollar value.
- A lab-grown report clearly says 'laboratory-grown'.
- Since late 2025, GIA no longer issues full D-to-Z grades on lab-grown stones — only IGI does.
- You can verify any report by its number on the lab's website.
- Many stones carry a tiny laser inscription of the report number on the girdle.
What a certificate is (and is not)
A grading report from an independent lab — IGI or GIA — tells you the objective facts about a diamond: its grades and dimensions, assessed by gemologists with no stake in the sale. It is not a valuation; for insurance you will also want an appraisal of replacement value. Think of the report as the spec sheet, the appraisal as the price tag.
Reading the report, field by field
| Field | What it tells you |
|---|---|
| Report number | The unique ID; use it to verify the report online |
| Shape & cutting style | e.g. round brilliant, oval, cushion modified brilliant |
| Measurements | The stone's dimensions in millimetres — its real, physical size |
| Carat weight | To two decimal places |
| Colour grade | D to Z — see diamond colour explained |
| Clarity grade | FL to I — see diamond clarity explained |
| Cut, polish & symmetry | The three grades that make Triple Excellent — see why it matters |
| Table % & depth % | The stone's proportions — see table and depth explained |
| Fluorescence | None to very strong — see fluorescence explained |
| Origin statement | States 'laboratory-grown' or 'natural' |
| Plot / comments | A diagram of any inclusions and their location, plus grader notes |
Reading the inclusion plot
The plot is the diagram section of the report, and it is worth a closer look on any stone near the top of the clarity scale. Red markings typically denote internal inclusions and green markings denote external (surface) characteristics; the shapes correspond to standardised symbols for feathers, pinpoints, clouds and similar features. At VVS1–VVS2 — the floor every Montare diamond meets — inclusions are, by definition, difficult even for a trained grader to find under 10x magnification, so a busy-looking plot at this clarity range usually reflects thorough documentation rather than a flaw you would ever see with the naked eye.
Every claim here is one you can check on the certificate — and we will walk you through a real one, no obligation.
Ask us anythingWhy the lab matters more than it used to
As of October 2025, GIA stopped issuing full D-to-Z colour grades and specific clarity grades on lab-grown diamonds. In their place, GIA now issues a simplified two-tier "Premium" or "Standard" classification. IGI has not made the same change — it continues to grade lab-grown stones on the complete 4Cs framework, the same detailed system used for mined diamonds. That is a meaningful difference if you are reading a report closely: a GIA lab-grown document from after October 2025 will not tell you whether a stone is D or E colour, or VVS1 or VVS2 clarity, only which broad tier it falls into. Every Montare diamond carries a full IGI report for exactly this reason. See what changed and why and our full IGI vs GIA comparison.
Red flags to check for
- No lab named. "Certified" with no lab specified, or a lab you cannot find online, is not verifiable.
- No report number, or a number that will not verify. A genuine report always resolves on the issuing lab's own website.
- Measurements that do not match the stone in hand. If you can compare, the millimetre dimensions should match what you are looking at.
- No plot or inclusion diagram on a stated high clarity. A VVS-or-better claim should still come with a documented plot.
- Origin statement missing entirely. A genuine report always states whether the stone is natural or laboratory-grown — it is not optional information.
How to verify a certificate
Never take a report on trust alone — verify it. Go to the IGI or GIA website, enter the report number, and confirm the details on screen match the document and the stone. Many diamonds also carry a microscopic laser inscription of the report number on the girdle (the edge), which a jeweller can show you under magnification. (More on the labs in IGI vs GIA.)
Certificate vs appraisal
The report grades quality; an appraisal estimates replacement value for insurance and can change with the market. You want both: the report to know what you have, the appraisal to insure it (see ring insurance in Canada).
The Montare standard
Every Montare diamond ships with its IGI report — graded D–E, VVS1–VVS2, Triple Excellent, three carats minimum — and full documentation, so what you read is exactly what you receive. Build one in the ring builder or book a consultation.
Bring us any diamond you are considering — ours or someone else's — and we will read the certificate with you and show you exactly what the grades mean. No obligation.
Book a free consultation →Frequently asked questions
What is on a diamond certificate?
The 4Cs (cut, colour, clarity, carat), the stone's measurements, table and depth percentages, fluorescence, a unique report number, an origin statement, and a diagram of any inclusions. For what those cut grades mean side by side, see what Very Good vs Excellent cut looks like.
Is a diamond certificate the same as its value?
No. A certificate grades quality; an appraisal estimates dollar value for insurance. They are different documents.
How do I verify a diamond certificate?
Enter the report number on the IGI or GIA website and confirm the details match the document and the stone. Look for the matching laser inscription on the girdle.
Do lab-grown diamonds come with a certificate?
Yes — reputable lab-grown diamonds are graded by IGI or GIA just like mined, with the report clearly stating 'laboratory-grown'.
Why does it matter whether a lab-grown diamond is IGI or GIA certified?
Since October 2025, GIA no longer issues full colour and clarity grades on lab-grown stones, only a simplified "Premium" or "Standard" tier. IGI still grades lab-grown diamonds on the complete 4Cs, which is why a specific claim like D colour or VVS1 clarity depends on having an IGI report.
What do the colours on a diamond plot mean?
Red markings generally show internal inclusions and green markings show external characteristics, using standardised symbols for feathers, pinpoints and clouds. A detailed plot on a VVS-grade stone is normal documentation, not a sign of a visible flaw.
What should I be suspicious of on a diamond certificate?
No named lab, a report number that will not verify on the lab's website, measurements that do not match the stone, or a high clarity claim with no inclusion plot at all.
Every stone, fully documented. Build one in the ring builder or book a consultation.
The Montare standard
Lab-grown · D–E colour · VVS clarity · Triple Excellent · 3ct minimum · IGI certified
Every ring is made to order in Toronto and backed by our lifetime setting upgrade, with free, fully insured shipping.
Book a free consultationDesign your ringFound this useful? Add Montare as a preferred source and our diamond guides will surface more often when you search.