Prepared by the Imperial Cushions editorial team. Laboratory terminology is retained where a report is cited; historical context and dealer judgment are identified as interpretation.
A laboratory report is essential documentation, but it is not a beauty certificate. Antique diamonds require a layered evaluation.
Begin with identity
Confirm natural origin, weight, measurements, colour, clarity, fluorescence and the report number. Check that the report corresponds to the stone being presented.
Then examine the face-up view
Look at outline, facet balance, brightness, contrast and how the culet sits within the pattern. Observe whether dark areas remain static or move naturally as the stone turns.
View the profile and condition
Crown height, depth, girdle condition and evidence of later repair or recutting can affect character and suitability for setting. Ask what is visible under magnification and what is not captured by the report.
Judge it in motion
On-hand and 360 degree videos are useful screening tools. Final decisions should be supported by direct inspection or an agreed independent professional whenever practical.