Grading scales
DIAMOND – INTERNAL Characteristics
| IF | Internally flawles at 10 magnifications |
| VVS – (VVS1, VVS2) | Very very small inclusions, very difficult to see at 10 magnifications |
| VS – (VS1, VS2) | Small inclusions, difficult to see at 10 magnifications |
| SI – (SI1, SI2) | Very small inclusions, easy to see at 10 magnifications |
| P – (P1, P2, P3) | Inclusions which can be found with the naked eye |
DIAMOND – cut grade
| PROPORTIONS | FINISH | POLISHING | FLUORESCENCE |
| excellent | excellent | excellent | none |
| very good | very good | very good | slight |
| good | good | good | medium |
| fair | fair | fair | strong |
| poor | poor | poor |
DIAMOND – color scale
| D E F | G H I J | K L M | N O P Q R | S T U V W X Y Z |
| Colorless | Near colorless | Faint yellow | Very light yellow | Light yellow |
TREATMENTS
The following classification of the most common treatments carried out on gems is used as a reference for the drafting of the analysis documents.
Treatments other than those described, will be specifically indicated in the comments.
| NTE | No indications of heating* |
| TE | Indications of heating |
| TE1 | Indications of heating with minor residues in fissures |
| TE2 | Indications of heating with minor residues in fissures |
| TE3 | Indications of heating with moderate residues in fissures |
| TE4 | Indications of heating with moderate residues in fissures |
| TE5 | Indications of heating with significant residues in fissures |
| F1 | Minor presence of foreign substances in fissures |
| F2 | Moderate presence of foreign substances in fissures |
| F3 | Significant presence of foreign substances in fissures |
| CR1 | Minor presence of foreign material in cavities |
| CR2 | Moderate presence of foreign material in cavities |
| CR3 | Significant presence of foreign material in cavities |
*The lack of diagnostic elements (NTE) for the determination of heat treatment does not absolutely guarantee that
the gem in question has not been subjected to this process.