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.
Read the comments line closely
The comments field often carries the most useful sentence on the report. Phrases such as “Clouds are not shown” or “Pinpoints are not shown” mean those characteristics are present but were left off the plot; they were still considered in the grade. On a laboratory-grown report, the comments may name the growth process and state whether the stone is as grown or shows indications of post-growth treatment. Other lines note surface graining, minor polish details, or the inscription. Read the comments before the grades, then read the grades with them in mind.
Worth remembering: A short comment can change how the rest of the report reads.
Not every report looks the same
Laboratories issue several report formats. Some shorter formats omit the clarity plot and rely on the girdle inscription to identify the stone; some reports are issued only as digital records. Formats also change over time, so an older report from the same laboratory may carry different fields. Note which format you are reading before concluding that something is missing.
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.
- Comments
- The report field for characteristics, processes, and notes not captured by the grades or the plot.
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?
- Which report format is this, and does it include a clarity plot?