Plotting is a system of drawing the inclusions and the surface characteristics of a diamond on a line diagram of the diamond. The process of plotting was developed in 1950 when the diamond grading system was developed. The main purpose of plotting is to identify the diamond at a future date. Plotting would naturally support the rate and value of the diamond in question.
When a diamond has many inclusions, the plotting process can be time-consuming. Plotting makes a diamond look worse than it is because small microscopic features are plotted larger on a diagram. With advances in laser technology, it became possible to make laser inscriptions on diamonds, and this process began in the 1980s. The inscription is etched on the girdle edge of the diamond. Laser inscriptions are more popular and GIA offers laser inscriptions instead of a plots for identification.
A brief description of laser inscription of diamonds and plotting are as follows:
Laser inscription on diamonds:
Laser inscription is a process of using a very fine laser beam to write a graphic logo or laboratory certificate number or customized personal message on the girdle. Laser inscription is considered permanent as it can only be removed by a professional diamond cutter. It does not change the color grade or clarity grade of a diamond. It is microscopic and not visible to the naked eye. It can only be seen through a jeweler’s 10x magnifying loupe.
Plotting of diamonds:
A plot is basically a diagram. It is like a fingerprint drawing with all the lines, curves and indentations of the diamond. Every diamond has inclusions in it. These inclusions are either visible to the naked eye or they are only visible under 10x magnification with microscope or 10x jeweler’s loupe. You can see a real plot of a diamond when you buy a certified diamond that has the plot drawn right on the report. The report shows two plots, one with a top-down view and another with bottom-up view.
In a diamond plot, you can see a bunch of marks like crystals, clouds, feathers, needles. You can also see things like pinpoints, cracks, breaks, fractures, bearding, growth lines, grain lines, cavities, knots, scratches, etc. Some certificates known as Dossiers, do not show you the plot of a diamond. These certificates will only have the details listed but will not show you where the inclusions lie. But the best thing about the Dossier reports is that all of them are laser inscribed diamonds.
Overall, there is no standard that exists for when a laser inscription would suffice, or when a plot should be performed for identifying the diamond. This is the personal choice of the labs and their policies as well as consumers and their preferences.
In either case, the originality and authenticity of the diamond is well-established.