(Ov-57, "Oval cut")
Cut this in plan view is a shape of an oval, cut – diamond (wedge-shaped). Faceted stone has 57 facets, 33 facets of the crown (the area of an octagonal shape, eight of the upper wedges of the crown, eight main crown facets of the diamond-shaped, sixteen pair of lower wedges of the crown) and 24 facets of the pavilion (sixteen pairs of wedges of the pavilion and eight main pavilion facets in the form deltoid).

The basic elements of a diamond cut shape "Oval"
(the settings are for optimal cut shapes)

The calculation of the weight

Calculate the weight (in carats) of the standard diamond cut "Oval" is produced by the basic formula:

M = L x B x H x k

where M – mass cut diamond, L is the length of the cut of a diamond, the width of the diamond, H be the height of the diamond, k – conversion factor metric measurements using the volume to mass, taking into account the geometry of the cut, and the density of diamond is 0,0062.
More precisely, a weight is determined taking into account the amendments on the thickness of the girdle, the convexity of the cut, the size of the faces of the chamfers, the size of the caletta and the ratio of the proportions of the cut.

The most famous of all historical diamonds oval in shape and similar in style to the modern brilliant cut blue diamond Wittelsbach. Modern brilliant cut with respect to the shape of the "oval" was introduced by Lazare Kaplan in the early 1960-ies.