Reports · Chapter 04
What a grading report does—and does not do
How to read identity, quality, proportions, comments, and laboratory limits in the right order.
A grading report is a disciplined record of a loose diamond at a point in time. It is useful precisely because its purpose is narrower than a sales pitch or an appraisal.
Begin with identity
Check the issuing laboratory, report number, report date, origin description, shape, carat weight, and measurements. If the girdle carries a report-number inscription, it can help connect the physical stone to the document, but the number and details should still be verified with the laboratory.
Read the quality results together
Color, clarity, and finish grades describe different observations. A cut grade, when the report provides one, has its own scope. Similar labels from different laboratories should not be assumed to use identical standards or report formats.
The proportion diagram is a map, not a verdict
The diagram records measurements and facet relationships such as table, total depth, crown, pavilion, girdle, and culet. Those values can screen for promising combinations, but they do not reproduce facet precision, transparency, or the full face-up pattern.
The clarity plot is approximate
Plotting symbols show the type and approximate position of selected characteristics. Not every feature is necessarily plotted, and comments may carry important information about characteristics, treatments, or inscriptions not fully represented elsewhere.
Verify at the issuing laboratory
Use the laboratory’s official report-check service and compare the archived information with the document and seller’s description. A matching number alone is not enough if carat, measurements, grades, or inscription details do not correspond.
Know where the paper ends
A grading report is not a guarantee, valuation, insurance appraisal, beauty certificate, or promise of durability. Videos, in-person viewing, setting design, seller terms, and independent professional advice answer different questions.
Worth remembering: The report establishes a common language; it does not make the decision.
Essential language
- Grading report
- A laboratory document describing a gem’s identity and quality characteristics.
- Report check
- An issuing laboratory’s service for verifying archived report information.
- Plot
- A diagram showing selected clarity characteristics and their approximate locations.
- Inscription
- Letters or numbers placed microscopically on the girdle.
- Finish
- Craftsmanship characteristics commonly reported as polish and symmetry.
Questions to take with you
- Does the official report-check record match every important detail on the document?
- Are origin and any treatments stated clearly?
- What appears in the comments or inscription fields?
- Which questions about appearance or condition still require imagery or inspection?