Patent ID: 6892720

Claim:
A method of cutting a diamond to obtain a high carat yield, the method comprising: forming a planar table lying in a table plane; forming a plurality of main crown facets to form a crown, said main crown facets oriented at an angle of between 26° and 35° relative to the table plane; forming a plurality of upper pavilion facets below the main crown facets at an angle of between 45° and 80° relative to a girdle plane lying between bottom edges of the main crown facets and top edges of the upper pavilion facets; and forming a set of lower pavilion facets between bottoms of the upper pavilion facets and a culet at an angle of between 38° and 44° relative to the girdle plane, the upper pavilion facets and the lower pavilion facets forming a rib line therebetween, said rib line positioned somewhere between one-fifth and four-fifths of a distance between the girdle plane and the culet, such that the upper pavilion facets extend between 20% and 80% of the distance between the girdle plane and the culet.