The facet count is the number of facets on a cut. On our cut pages, it is the number of planar faces of the cut's STEP solid.
In more detail
A cutting design can count differently. A turned girdle is one surface in a solid but many facets on the machine. Then the page gives both counts. The T73 round brilliant has 73 facets: 57 plus 16 girdle facets.
How we measure it
Our scintillation score uses the number of facets that reach the surface of the cut.
Related terms
- Facet: A facet is one flat, polished face of a cut gemstone. Its angle and its direction around the stone decide where it sends light.
- Scintillation: Scintillation is the pattern of light and dark flashes a stone shows as it, the light or the viewer moves. Our score reads it from the number of facets that reach the surface of the cut.
- STEP file: STEP is a standard CAD format that stores an exact solid, with each facet as a true plane. CAD programs such as FreeCAD, Rhino and Fusion open it to measure a stone and design a setting.
- Turned girdle: A turned girdle is a girdle with a smooth round edge, shaped as a cylinder, instead of flat girdle facets. CAD often gives a round stone this kind of girdle.