A polished stone lands on your bench with a GIA report folded inside the parcel. Most retailers scan the report number, the carat weight, and the color grade, then move on. A wholesale buyer who reads every line catches the stones that will return as complaints: poorly proportioned cuts, comments about coatings, and inclusions that sit under the main facet. This guide walks through a modern GIA Diamond Grading Report from top to bottom.
Header: report number, shape and measurements
The top block carries the 10-digit report number, the shape and cutting style (for example, "Round Brilliant"), and measurements in millimeters (for example, 6.40 - 6.44 x 3.96 mm). The millimeter range tells you girdle roundness; a spread above 0.15 mm on a 6.4 mm stone signals a slightly out-of-round girdle that may seat poorly in a head. Carat weight is reported to two decimals (1.02 ct). Compare it to your invoice weight; a 0.01 ct gap after recut is normal, a 0.03 ct gap is not.
Color and clarity grades
The color grade runs from D (colorless) to Z (light yellow). Engagement buyers in the trade usually target D through H for white metal, and I through J for yellow gold, where the warmer tint blends in. The clarity grade runs FL, IF, VVS1, VVS2, VS1, VS2, SI1, SI2, I1, I2, I3. Trade selling to consumers stocks VS-SI eye-clean stock; anything I1 and below needs disclosure in the listing.
Cut grade and proportions
Round brilliants carry a cut grade from Excellent down to Poor. Fancy shapes do not receive a cut grade from GIA, so you read the proportions diagram instead: table percent, depth percent, crown angle, pavilion angle, girdle thickness, and culet size. A round stone with table 55-60%, depth 60-63%, crown angle 34-35 degrees and pavilion 40.6-41.0 degrees is the trade sweet spot. Deviations outside those brackets lose 10-20% resale value.
Comments and the inscription
The Comments box is where coatings, fracture filling, laser drilling, and recutting are disclosed. "No indications of heating" on a colored stone is a selling point; "coated" or "fracture filled" means the stone must be sold as treated. The bottom of the report lists the laser inscription that matches the report number and is etched on the girdle. Verify it under 10x before accepting a parcel.
For how these grades map onto sourcing decisions, see the 4Cs explained for trade buyers and our note on GIA versus IGI reports for lab-grown parcels.
Common report defects that fail intake
Three defects come up in roughly 5% of trade parcels. First, the inscription number on the girdle does not match the report number on paper — this flags either a swapped stone or a re-used report. Second, the measurements listed on the report differ from the measured stone by more than 0.10 mm, indicating a recut after grading. Third, the Comments box mentions "additional clouds" or "feather not shown" — that is a disclosure the consumer listing must repeat. Wholesale buyers who photograph the report, the stone on a mm gauge, and the girdle inscription in one intake sheet eliminate 90% of disputes.
FAQ
What is the difference between a GIA Diamond Grading Report and a Diamond Dossier?
The Dossier is a shorter document for stones under 2 ct; it omits the full proportion diagram but keeps the same grades and girdle inscription.
Can I look up a GIA report online?
Yes. GIA's Report Check tool at gia.edu lets you enter the report number and confirm shape, carat, color, and clarity match the paper document.
Does GIA grade moissanite?
No. GIA grades natural and lab-grown diamond. Moissanite is papered by independent labs such as GRA; see our guide on moissanite sourcing.
What does "culet: pointed" mean?
Culet describes the bottom facet. Pointed or none is ideal; a large culet lets light leak through the bottom of the stone.
Verify before you pay
Cross-check the report number in Report Check, inspect the girdle inscription under a loupe, and weigh the stone on a calibrated scale. Reject any parcel where the paper weight, measured size, or color grade does not match. Official field definitions are published by GIA's 4Cs documentation; lab-grown counterparts are covered by IGI reporting standards.
Wholesale note: gemmanufacturer.com ships certified diamond and lab-grown parcels with report numbers pre-registered in Report Check, so buyers can verify every stone at intake.
One extra habit worth adopting: photograph the report, the stone on a digital caliper, and the girdle inscription in a single intake folder for every parcel. When a client later asks whether the stone matches its paper, that folder answers in seconds instead of days.
For bridal parcels, also note whether the report lists "no fluorescence" or medium blue fluorescence; fluorescence is not a defect, but it changes under UV light and should be disclosed in the listing.
