Durability is the part of GIA's cut grade that checks for a risk of damage. The risk comes from a very thin girdle or thin points.
In more detail
It is one of the two design components of the cut grade, with weight ratio. GIA does not count a shallow crown as a risk unless the girdle is also very thin. In our Cut Grading Tool, which reads GIA's tables, a Very Thin girdle limits a T73 to Very Good. An Extremely Thin girdle limits it to Good.
On a grading report
Not printed on its own line: read it from the girdle description.
Related terms
- Girdle thickness: Girdle thickness is how thick the girdle is at its thinnest and thickest points. A report gives it as a range of words, such as "Thin to Medium".
- Weight ratio: Weight ratio is the part of GIA's cut grade that compares a diamond's weight with its diameter. A stone can carry too much or too little weight for its width.
- Cut grade: The cut grade rates how well a diamond's proportions and finish work, from Excellent to Poor. GIA gives it only to standard round brilliants in the D-to-Z color range.
- Girdle: The girdle is the narrow band at the widest part of a cut stone, between the crown and the pavilion. It is the edge that a setting grips.