New-cut diamond shape

A diamond piece having a crown or bezel and a pavilion converging up and down from its girdle respectively, the shape or proportion of said diamond piece being defined by:

• the whole height of the diamond piece being equal to or substantially equal to 64% of the diameter of the girdle;
• the height of the crown being equal to or substantially equal to 15.7% of the diameter of the girdle;
• the height of the pavilion being equal to or substantially equal to 48.3% of the diameter of the girdle;
• the largest width of the girdle being equal to or substantially equal to 1.2 to 1.4% of the diameter of the girdle;
• the diameter of a tangential circle of the polygonal table is 50 to 53% of the diameter of the girdle, the polygonal table having sides equal to the integer multiple of three;
• the crown has star facets, upper-main facets and upper-girdle facets formed thereon, whereas the pavilion has lower-girdle facets and lower-main facets formed on its converging surface and has sectors delimited by keel lines which extend from intersections of bisectors each extending between adjacent reference lines passing through respective apexes of the polygonal table and the girdle-tangential circle to the bottom center of the pavilion, at which bottom center a culet is formed, the lower-main facets converging to the culet.