How to Read an IGI Certificate — Full Report vs Card Certificate
When purchasing a lab-grown diamond, an IGI certificate ensures authenticity and provides key insights into quality. However, not all certificates are the same. Here we explain the differences between a full IGI report and a card-type certificate, and why MadisonDia recommends the full report. MadisonDia only offer full IGI report Lab grown diamonds.
What is Included in an IGI Full Report on Lab Grown Diamond?
The full IGI report contains comprehensive grading details, allowing consumers to evaluate their diamond with confidence. It includes:
- Cutting Style – Round Brilliant, Oval, Pear, Cushion, etc.
- Measurements – Millimeter dimensions of the stone.
- Carat Weight – Exact weight to two decimal points.
- Color Grade – From D (colorless) to Z (light color).
- Clarity Grade – From Flawless (FL) to Included (I3).
- Cut, Polish, and Symmetry – Detailed grading of craftsmanship.
- Fluorescence – Presence of UV fluorescence.
- Comments – Such as “No indication of post-growth treatment,” meaning the diamond has not undergone enhancements after growth. This assures transparency in quality.
- Growth Method – HPHT or CVD.
- Detailed Proportions – Including table %, depth %, crown angle, pavilion angle, girdle thickness, and culet size.
- Clarity Characteristics Plot – A map of inclusions and blemishes unique to your stone, similar to a fingerprint.
Recommended Proportions for Round Brilliant Diamonds
To ensure maximum brilliance and fire, experts recommend the following proportions:
| Parameter | Recommended Range |
|---|---|
| Table % | 54% – 57% |
| Depth % | 61% – 62.5% |
| Crown Angle | 34° – 35° |
| Pavilion Angle | 40.6° – 41° |
| Girdle Thickness | Thin – Medium |
| Culet | None – Very Small |
The 4Cs Charts for Lab Grown Diamond
Diamond Color Scale
| Grade | Description |
|---|---|
| D – F | Colorless |
| G – J | Near Colorless |
| K – M | Faint Color |
| N – R | Very Light Color |
| S – Z | Light Color |
Diamond Clarity Scale
| Grade | Description |
|---|---|
| FL – IF | Flawless / Internally Flawless |
| VVS1 – VVS2 | Very Very Slightly Included |
| VS1 – VS2 | Very Slightly Included |
| SI1 – SI2 | Slightly Included |
| I1 – I3 | Included |
Diamond Cut Grades
| Grade | Description |
|---|---|
| Excellent | Optimal brilliance and fire |
| Very Good | High brilliance with slight differences |
| Good | Noticeable variations in brilliance |
| Fair | Limited sparkle |
| Poor | Dull, little brilliance |
Carat Weight
Carat weight measures diamond size, but brilliance depends more on proportions and cut quality. A well-cut 1.0ct diamond can appear larger and more brilliant than a poorly cut 1.2ct stone.
What is an IGI Card Certificate for lab grown diamond?
The IGI card certificate is also an official document but contains significantly less detail. It typically includes:
- Cut and Shape
- Carat Weight
- Color Grade
- Clarity Grade
- IGI Laser Inscription Number
-
However, it does not provide proportions, polish, symmetry, fluorescence, growth method, or clarity characteristics.
Full Report vs Card Certificate — Key Differences
| Feature | IGI Full Report | IGI Card Certificate |
|---|---|---|
| Cutting Style | ✔ | ✔ |
| Measurements | ✔ | ✘ |
| Carat Weight | ✔ | ✔ |
| Color Grade | ✔ | ✔ |
| Clarity Grade | ✔ | ✔ |
| Cut Grade | ✔ | ✘ |
| Polish & Symmetry | ✔ | ✘ |
| Fluorescence | ✔ | ✘ |
| Proportions | ✔ | ✘ |
| Clarity Characteristics Plot | ✔ | ✘ |
| Growth Method (CVD/HPHT) | ✔ | ✘ |
| Comments (e.g., No Post-Growth Treatment) | ✔ | ✘ |
Why MadisonDia Recommends lab grown diamond with Full IGI Report
Although IGI card certificates are cheaper, our expertise shows that laboratories often reserve lower-quality stones for this option. For example, a diamond may have a D color and VVS1 clarity, but if the cut is poor, it will lack brilliance. By only issuing a simple card certificate, the lab avoids full grading exposure.
For consumers seeking long-term value and transparency, MadisonDia strongly recommends purchasing diamonds with a full IGI report. This ensures you understand the complete profile of your diamond and can be confident in both beauty and value.
Visit IGI official site for how to read igi report.
FAQ-How to Read an lab grown diamond IGI Certificate
Q: What is an IGI certificate? A: An IGI (International Gemological Institute) certificate is a document that verifies the authenticity and quality of a diamond, often a lab-grown one.
Q: What is the difference between a full IGI report and a card certificate? A: A full IGI report is a comprehensive document that provides extensive details about the diamond, including its proportions, clarity characteristics, and the growth method used. A card certificate, on the other hand, is a smaller document with significantly less information, typically only listing the carat weight, color, clarity, and the IGI laser inscription number.
Q: Why is a full IGI report recommended over a card certificate? A: The article recommends a full report because it provides a complete understanding of the diamond's profile, including crucial details about its cut, polish, and symmetry. These factors are essential for the diamond's brilliance and value, and they are not included on the card certificate.
Q: What information is included in a full IGI report? A: A full report includes details such as the diamond's cutting style, measurements, carat weight, color and clarity grades, cut, polish, symmetry, fluorescence, growth method (HPHT or CVD), detailed proportions, and a clarity characteristics plot.
Q: Can a diamond with good color and clarity still be of low quality? A: Yes. According to the article, a diamond with good color and clarity can still lack brilliance and beauty if it has a poor cut. This is a key reason why a full report, which provides cut details, is important.
Author Bio— Winston Wu, Marketing Directors of Kardias Fashion Group, has focused on luxury procurement since 2012, deeply collaborating with European first-tier brands such as Versace, Moschino, Hugo Boss, and Roberto Cavalli, with rich practical experience in the diamond market.
Publication Date: 27 August 2025 Last Updated: 4 September 2025
Disclaimer: The price information provided in this article is based on January 2025 market data. Actual prices may vary due to market fluctuations. Please confirm the latest quotes with vendors before purchasing. This article does not constitute investment advice.
This article is jointly published by Luxury Boutique Madison Avenue
