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.
In more detail
A thick enough girdle protects the edge from chips. It can be bruted, polished or faceted, and graders judge the thickness the same way for all three. The T73 has a girdle band of 16 facets; the T57 has a knife-edge. Labs also use the girdle for inscriptions.
On a grading report
On the proportion diagram as a thickness description and a percentage, with the girdle finish (faceted, polished or bruted).
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".
- Knife-edge girdle: A knife-edge girdle has no girdle band at all: the crown and the pavilion meet in a sharp line.
- Inscription: An inscription is text that a laser writes on the girdle of a stone, too small to see without magnification. Most often it is the report number.
- Crown: The crown is the part of a cut stone above the girdle. On a standard round brilliant it has 33 facets: the table, 8 stars, 8 bezels and 16 upper halves.
- Pavilion: The pavilion is the cone-shaped part of a cut stone below the girdle. A standard round brilliant has 24 pavilion facets: 8 mains and 16 lower halves.
- Bearded girdle: A bearded girdle has very small feathers that run from the girdle surface into the stone. They can come from the cutting process.