The keel is the short line at the bottom of the pavilion of an elongated stone, such as a marquise. A round has a point there.
In more detail
All pavilion facets slope down from the girdle to the keel. Facets that start near the center must slope steeply, and facets far out toward a point slope gently. That spread of angles is why elongated stones can show a bow-tie.
Related terms
- Belly: The belly is the wide middle of an elongated stone such as an oval, pear or marquise.
- Culet: The culet is the bottom point of the pavilion. It can also be a tiny facet, parallel to the table, that keeps the point from chipping.
- Bow-tie: A bow-tie is a dark band across the belly of an oval, pear, marquise or other elongated stone. It is not an inclusion or a color: the facets there send little light back to the viewer.
- Marquise cut: A marquise cut is an elongated brilliant pointed at both ends.