The clarity plot and the laser inscription are two of the identifying details on a GIA diamond report. The plot is a map of the stone's clarity characteristics, drawn on a crown view and a pavilion view. A laser inscription, when there is one, is a microscopic mark on the girdle, most often the report number. Together they help you match the report to the diamond in front of you. They are easy to skim past, but they are among the most useful parts of the paperwork once you are choosing a stone.
What the clarity plot shows
GIA describes the plotting diagram as a map of a diamond's clarity characteristics: the inclusions inside the stone and the blemishes on its surface. The diagram is made to match, or closely resemble, the shape and facet arrangement of the diamond, and it is drawn from what a grader sees under 10 times magnification. Because no two diamonds have the same diagram, GIA also treats it as a means of identification, and as a record of the stone's condition when it was graded.
The plot uses a simple colour key. Red marks most inclusions. Green marks naturals, which are remnants of the original crystal surface. Black marks extra facets. Red and green together are used for a smaller group of features, such as cavities, indented naturals, knots, etch channels and laser drill holes. Beside the diagram, a Key to Symbols lists the features in order of their importance to the clarity grade. GIA notes that some faint or widespread characteristics are not plotted, though they may appear in the comments. Our guides to inclusion types and to what an eye clean diamond is explain what those marks can mean in the hand.
When a report has no plot, and what an inscription is
Not every GIA document uses a plotting diagram. GIA explains that on a Diamond Dossier or a Diamond eReport, the same clarity standards are used, but up to four of the significant clarity characteristics are listed in words instead. A laser inscription or a digital image of the diamond may be provided to help identify it. That is worth knowing before you compare two reports that look slightly different on the page.
GIA can also inscribe the girdle microscopically with the unique report number, or with a symbol, a logo or a short personal message. The inscription is not visible to the naked eye and is intended to be read under 10 times magnification. If the stone has one, it is listed on the report under inscriptions. It is a practical way to match the diamond to the paperwork, not a decoration you will see when the ring is on the hand. Our guide to how to read a GIA certificate sets this in the context of the rest of the report.
How we use them when we shortlist stones
When we look at a report with you, we read the plot or the listed characteristics next to the clarity grade, then we look at the diamond on a video consultation. A mark that looks important on the diagram may be very hard to see in the setting; the opposite can also be true, which is why the paperwork and the stone have to be considered together. Our guide to the 4Cs explains how clarity sits with cut, colour and carat.
Nothing is made until you approve the design and the stone in writing. A 70 percent deposit is paid then, making time is 5 to 6 weeks, and the ring is UK hallmarked before insured, tracked FedEx delivery. If you would like to go through a report with us, get in touch or browse the diamonds we can source.
Frequently asked questions
What is the clarity plot on a GIA report?
It is a map of the diamond's clarity characteristics, shown in a crown view and a pavilion view. GIA uses it to support the clarity grade and as a way to identify the stone, because no two plots are the same.
Does every GIA report include a plotting diagram?
No. A full GIA Diamond Grading Report includes a plotted diagram. On a GIA Diamond Dossier or a GIA Diamond eReport, GIA instead lists up to four of the most significant clarity characteristics, and may include a laser inscription or a digital image to help identify the stone.
What is a laser inscription?
GIA can microscopically inscribe a report number, a symbol, a logo or a short message on the girdle of the diamond. It is not visible to the naked eye and is meant to be read under 10 times magnification. The inscription, if there is one, is listed on the report.
Can you see the plot or the inscription in a photograph of the ring?
Usually not. The plot lives on the report, and a laser inscription on the girdle is too small to see in ordinary light. We look at the report with you, and at the diamond on a video consultation, rather than asking you to find those marks in a photograph.