The key to symbols is the list beside the clarity plot. It names the kinds of clarity characteristic on that plot.
In more detail
GIA lists them by importance to the grade. A laser drill hole comes first, then grade-setting inclusions, other inclusions, naturals and extra facets. On the plot, red shows most inclusions, green shows naturals and black shows extra facets. Cavities, indented naturals, knots, etch channels and laser drill holes use red and green together.
On a grading report
Beside the plotted diagram on a full GIA Diamond Grading Report.
Related terms
- Clarity plot: The clarity plot is the map on a full grading report: an outline of the stone with symbols on it. Each symbol shows the type, position and approximate size of a clarity characteristic.
- Laser drill hole: A laser drill hole is a tiny, surface-reaching tunnel made by a laser beam, usually toward a dark inclusion.
- Inclusion: An inclusion is a clarity characteristic inside a diamond, or one that reaches the surface from inside.
- Blemish: A blemish is a clarity characteristic confined to the surface of a diamond.
- Natural: A natural is a part of the rough diamond's original surface left on the cut stone. It is usually on or near the girdle.
- Extra facet: An extra facet is a facet that the cutting style doesn't need, placed without regard for the stone's symmetry. It is most often near the girdle.