The intersections of the upper and lower main and girdle facets should lie on the girdle exactly opposite one another, and not be displaced sideways in relation to one another.
Such edge displacements clearly affect the regularity of the cut. An edge displacement which extends beyond a quarter of the length of the edge and into the adjoining facet causes reduced brilliance. Such displacements automatically lead to an uneven girdle and spoil its regularity (Fig 286-289).
Displaced edges which affect the symmetry and lower the grade of cut can sometimes be observed where facets meet (Fig 290 and 291).
|Fig 291 a Various long pavilion facets.||Fig 290 Transposed facet edges of the crown||Fig 291 b Various long pavilion facets|
|Regularity of the facets||Size of the culet|