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:
- 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).
- 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)?
- The grades. Color (look for an asterisk), clarity, and a cut grade only where the lab gives one (see the grades). If "Ideal" appears anywhere, which kind is it (see what "Ideal" means)?
- The finish. Polish and symmetry: do they allow the cut grade? Fluorescence: strength and color, not a grade (see polish, symmetry and fluorescence).
- The diagrams. A clarity plot on a full report, a written list on a Dossier (see the clarity plot). The proportion diagram: does the total depth match the measurements (see the proportion diagram)?
- The fine print. Comments, treatments, inscriptions, origin (see comments, treatments and 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
- Run the checklist on the practice sheet above. Write down every line that can't be right, and why.
- Then open 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.
- Open the simulator's PDF report and run the same checklist on it.
What the checklist finds
The five errors:
- 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.
- 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.
- The cut grade. Good polish caps a GIA round at Very Good. Excellent can't stand next to it.
- The plot. A Dossier has no plotted diagram. It lists up to four characteristics in words instead.
- 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.
Try it free
- 3D Gemstone Simulator: Turn a cut in seven gemstones and set its carat, color, clarity and cut grade.
- 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.
Keep exploring
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