Introduction
Every GIA Diamond Grading Report includes a pair of small facet-outline diagrams marked with coloured symbols. This is the clarity plot — and it contains more actionable information than the clarity grade alone.
The grade tells you how clean a diamond is. The plot tells you where and what kind of characteristics earned that grade. Two VS2 diamonds at the same price may differ significantly: one with a crystal tucked near the girdle, invisible once set; another with a feather under the table, visible at arm's length. The plot reveals the difference.
This article explains how to read the clarity plot on reports from GIA, HRD Antwerp, and IGI. For the underlying clarity concepts and a deeper treatment of each symbol, see Plot and Comments.
Key Points
Where the plot appears
On a GIA Diamond Grading Report (full format), the clarity plot sits in the lower-left area of the first page, below the grading results. Two facet outlines appear side by side: crown view on the left, pavilion view on the right. On the GIA Diamond Dossier (compact format for smaller stones), the plot is omitted — only the grade and comments appear.
HRD Antwerp and IGI full reports include comparable plots using the same red-green colour coding and similar symbol conventions. Layout varies, but the data is equivalent.
Regardless of laboratory, the plot is always paired with a comments section. The two must be read together — the plot shows what can be mapped; the comments disclose what cannot. See Report Comments.
Crown and pavilion views
The crown view (top-down) shows characteristics as seen looking through the table — the angle that matters most, because it represents how you see the diamond when worn. The pavilion view (bottom-up) shows features deep within the stone. A dark crystal near the culet on the pavilion view may be reflected multiple times by pavilion facets, appearing as a pattern of dark spots when viewed from above.
When a characteristic appears on both views, it spans significant depth within the stone — potentially more relevant to durability than a shallow feature on one view only.
Red and green: inclusions vs blemishes
Red symbols — inclusions. Internal features: crystals, needles, feathers (contained), clouds, pinpoints, twinning wisps. Permanent — cannot be removed without re-cutting. A red-dominated plot means the grade is driven by internal structure.
Green symbols — blemishes. Surface or surface-reaching features: nicks, scratches, naturals, extra facets, cavities, surface-reaching feathers. Some can theoretically be reduced through re-polishing, though this involves material loss. A green-dominated plot suggests surface characteristics drive the grade.
For the full distinction, see Inclusions vs Blemishes.
Common symbol legend
| Symbol | Characteristic | Colour | What it is |
|---|---|---|---|
| Small dot | Pinpoint | Red | Microscopic included crystal |
| Thin line | Needle | Red | Long, slender included crystal |
| Branching line | Feather | Red / Green | Internal fracture (red if contained; green if surface-reaching) |
| Shaded area | Cloud | Red | Cluster of pinpoints creating a hazy region |
| Irregular ribbon | Twinning wisp | Red | Complex formation along a twin plane |
| Solid shape | Crystal | Red | Trapped mineral — colourless, white, or dark |
| Small opening | Cavity | Green | Surface void from a dislodged inclusion |
| Bump symbol | Knot | Green | Included crystal extending to the surface |
| Rough girdle area | Natural | Green | Remnant of original rough crystal surface |
| Extra facet outline | Extra facet | Green | Additional polished facet, often placed to remove a near-surface inclusion |
Diamonds graded VS and above typically show only two or three symbol types. For detailed descriptions, see Clarity Characteristics.
What the plot does not show
No relief or colour. The same crystal symbol represents a nearly invisible colourless inclusion and a conspicuous dark garnet. Only images or inspection reveal the difference.
No proportional size. Symbols show position and type, not precise dimensions.
No visual impact in motion. A prominent-looking symbol may be masked by brilliance during wear; a minor-looking one may flash conspicuously at certain angles.
No diffuse transparency effects. Widespread cloudiness and scattered pinpoints affect overall transparency but cannot be represented by individual symbols. This is why comments like "additional clouds are not shown" or "clarity grade is based on clouds that are not shown" matter — they signal what the plot cannot convey. See Cloud Inclusions & Transparency.
Using the plot to evaluate a diamond
Check position relative to the table. Characteristics under the table on the crown view are the most visible face-up. Those near the girdle are typically concealed by prongs or bezel. A VS2 with its inclusion near the girdle may look cleaner than an SI1 with a characteristic dead centre.
Assess the pavilion for reflections. A dark crystal near the culet can be reflected symmetrically, appearing as multiple dark spots through the table. If you see a crystal symbol near the centre of the pavilion view, request photographs.
Check for durability risk. Most characteristics are harmless. The exception: large feathers reaching the girdle edge, particularly in thin girdle areas, which create a potential chipping point during setting or wear. See Durability Risk from Inclusions.
Read the comments. A plot that looks clean but carries "clarity grade is based on clouds that are not shown" tells a different story. The comments complete the picture.
When comparing two stones: prefer fewer symbols under the table over fewer symbols overall — position matters more than quantity. Check whether the comments differ; two SI1 diamonds with similar plots can diverge significantly if one carries a "clouds not shown" note.
Czech Consumer Note
Under EU consumer protection regulations, Czech retailers must provide accurate documentation for graded diamonds, including the clarity plot. If a seller describes a diamond as "eye-clean" but the plot shows a large crystal under the table, request crown-perspective photographs to verify. When purchasing online, always request a high-resolution report scan — low-resolution images that obscure plot symbols make informed evaluation impossible.
Summary
The clarity plot is the most informative diagram on a diamond grading report. Two facet outlines map every characteristic by type (symbol), category (red for inclusions, green for blemishes), and position (crown vs pavilion view). The comments section completes the picture with what the plot cannot represent.
Read the plot with position in mind. Under the table matters most. Near the girdle matters least. A feather at the girdle may affect durability. A crystal near the culet may create reflections. These are judgements the clarity grade cannot make for you — but the plot gives you the information to make them yourself.