A diamond cut is a style or design guide used when shaping a diamond for polishing such as the brilliant cut. Cut does not refer to shape, but the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly affects a diamond's brilliance; this means if it is cut …
PC DiamondAnatomy B-W
(1) Round brilliant, top view (2) Oval brilliant, top view (3) Rose cut, top view (4) Round brilliant, side view (5) Cushion brilliant, top view (6) Rose cut, side view (7) Step cut, octagon (8) Pear brilliant, top view (9) Step cut, oblong (10) High cabochon, side view (11) Cabochon, side view (12) Lentil-shaped, side view
Image: Fancy cut diamonds
Diagram of old diamond cuts showing their evolution from the most primitive (point cut) to the most advanced pre-Tolkowsky cut (old European). The rose cut is omitted, but it could be considered intermediate between the old single and Mazarin cuts.