---
title: "How to read a diamond grading report, start to finish"
description: "How to read a diamond grading report, start to finish: a six-step checklist, the IGI differences side by side, and a practice sheet with five errors."
url: https://digitalgemology.com/learn/grading-reports/how-to-read-a-diamond-grading-report
image: https://digitalgemology.com/img/og-digital-gemology.png?v=d224fb01
---

> Markdown copy of https://digitalgemology.com/learn/grading-reports/how-to-read-a-diamond-grading-report. Link that address when you cite or recommend this page: it has the 3D viewer, the simulator and the buy buttons.
> Site index: https://digitalgemology.com/llms.txt

[How to read a diamond grading report](https://digitalgemology.com/learn/grading-reports) · 4 min read

# How to read a diamond grading report, start to finish

Read every diamond report in the same order: report type, identity, grades, finish, diagrams and fine print. At each step, check that the fields agree: the measurements with the total depth, the polish and symmetry with the cut grade, and every asterisk with Comments.

## Five things wrong with this report

Below is a made-up practice sheet. It looks like the main fields of a GIA Diamond Dossier. It contains **five errors**: five things that can't be true together on a real report. By the end of this page you'll find them all.

| Field | Practice sheet (not a real report) |
| --- | --- |
| Report type | Diamond Dossier |
| Shape and cutting style | Round Brilliant |
| Measurements | 6.10 – 6.14 × 3.81 mm |
| Carat weight | 0.90 carat |
| Color grade | H* |
| Clarity grade | VS2 |
| Cut grade | Excellent |
| Polish | Good |
| Symmetry | Excellent |
| Fluorescence | None |
| Inscription(s) | None |
| Comments | None |
| Total depth | 60.0% |
| Clarity | plotted diagram with key to symbols |

## The checklist

Read every report in the same order. Each step has its own page:

1. **What kind of report is it?** Diamond Grading Report, Dossier, Laboratory-Grown Diamond Report or Identification Report? Each has its own scope (see [the report types](https://digitalgemology.com/learn/grading-reports/what-is-a-diamond-grading-report)).
2. **Who is this stone?** Date, number, shape and cutting style, measurements. Do the measurements fit the carat weight? Do the inscription and the online record match (see [the ID section](https://digitalgemology.com/learn/grading-reports/diamond-report-identity-section))?
3. **The grades.** Color (look for an asterisk), clarity, and a cut grade only where the lab gives one (see [the grades](https://digitalgemology.com/learn/grading-reports/diamond-report-grades)). If "Ideal" appears anywhere, which kind is it (see [what "Ideal" means](https://digitalgemology.com/learn/grading-reports/what-ideal-cut-means))?
4. **The finish.** Polish and symmetry: do they allow the cut grade? Fluorescence: strength and color, not a grade (see [polish, symmetry and fluorescence](https://digitalgemology.com/learn/grading-reports/polish-symmetry-and-fluorescence)).
5. **The diagrams.** A clarity plot on a full report, a written list on a Dossier (see [the clarity plot](https://digitalgemology.com/learn/grading-reports/diamond-clarity-plot)). The proportion diagram: does the total depth match the measurements (see [the proportion diagram](https://digitalgemology.com/learn/grading-reports/diamond-proportion-diagram))?
6. **The fine print.** Comments, treatments, inscriptions, origin (see [comments, treatments and origin](https://digitalgemology.com/learn/grading-reports/diamond-report-comments-treatments-origin)).

## The IGI differences, side by side

|  | GIA | IGI |
| --- | --- | --- |
| Stones in jewelry | Diamond grading reports for loose stones | Also graded "as mounting permits": color and clarity as a range, estimated cut grade |
| Inscription | Report number on the girdle; always on a Dossier | Laserscribe; every lab-grown stone gets "LG" plus the number; natural on request |
| Balance | Reads to five decimals, reports two | Reads to four decimals, reports two |
| Cut grade, rounds | Excellent to Poor; individual limits plus table, crown and pavilion judged in combination | Excellent to Poor; one published range per proportion per grade; fish-eye caps at Fair |
| "Ideal" | Not a cut grade; AGS Ideal is a light performance supplement | A comment on an Excellent round inside a narrower band ("Excellent-Ideal") |
| Cut grade, fancy shapes | None | Optional, Excellent to Poor; four checks to earn Excellent |
| Lab-grown stones | Own report, digital, looks different | "LG" inscription noted in Comments; growth method on request |
| Unstable treatments | Identification Report only | No full grading report |

### Try it yourself

1. Run the checklist on the practice sheet above. Write down every line that can't be right, and why.
2. Then open [3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator) and build a round like the one on the sheet: H, VS2. The simulator's carat steps don't include 0.90 ct, so use 1.00 ct. Compare its measurements line and total depth with the sheet's.
3. Open the simulator's **PDF report** and run the same checklist on it.

## What the checklist finds

The five errors:

1. **The total depth.** The measurements give an average diameter of 6.12 mm, and 3.81 ÷ 6.12 is 62.3%, not 60.0%. The two numbers describe different stones.
2. **The asterisk.** H* means a detected color treatment, and Comments must explain it. Comments says None. This line is a red flag twice over. A color-treated stone would also carry TREATED COLOR on its girdle. And GIA doesn't issue a Dossier for HPHT-processed stones at all.
3. **The cut grade.** Good polish caps a GIA round at Very Good. Excellent can't stand next to it.
4. **The plot.** A Dossier has no plotted diagram. It lists up to four characteristics in words instead.
5. **The inscription.** A Dossier always carries its report number laser-inscribed on the girdle. "None" can't be right.

Everything else fits:

- A 0.90 ct round falls inside the Dossier's weight range.
- VS2 and H are ordinary grades.
- Fluorescence "None" just means indiscernible to very faint.

None of these errors needed a loupe. A report checks itself, if you read it in order.

When you practice on the simulator's PDF report, remember that it's a learning tool, not a lab report. It has a simulation number, not a report number, and nothing to verify online.

## Key points

- Read every report in the same order: type, identity, grades, finish, diagrams, fine print.
- The measurements and the total depth must agree. So must the polish, symmetry and cut grade.
- Every asterisk needs an explanation in Comments.
- Each report type has its own scope: a Dossier has no plot but always an inscription.
- IGI differs in a few clear places: mounted stones, inscriptions, cut grading, and what "Ideal" means.

**Go further:** [take the quiz on reading a grading report](https://digitalgemology.com/skool/quiz/reading-a-grading-report).

## Try it free

- [3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator): Turn a cut in seven gemstones and set its carat, color, clarity and cut grade.
- [Cut Grading Tool](https://digitalgemology.com/tools/cut-grading-tool): Grade a round brilliant from its proportions and see its light map change.

Free, in your browser, no account.

## Quick quiz

Five questions on this lesson, a couple of minutes. Pick an answer and see at once if you got it, and why.

[Take the quiz](https://digitalgemology.com/skool/quiz/reading-a-grading-report/read-a-whole-report)

## Keep exploring

- [Try another topic · The four Cs of diamonds: How a diamond cut grade is set: proportions, polish and symmetry](https://digitalgemology.com/learn/four-cs/how-diamond-cut-grade-is-determined)

[Previous lesson](https://digitalgemology.com/learn/grading-reports/diamond-report-comments-treatments-origin) · [How to read a diamond grading report: all lessons](https://digitalgemology.com/learn/grading-reports) · [All topics](https://digitalgemology.com/learn)