The lozenge cut is a four-sided fancy cut whose outline forms a rhombus or diamond shape, with two acute and two obtuse corners. It is essentially a step-cut variant of the kite, with parallel sides arranged so that the long and short axes intersect at unequal angles. The cut takes its name from the heraldic lozenge, the diamond-shaped charge used in coats of arms, and has been employed in jewellery since at least the late medieval period.

Geometry

A lozenge has four equal sides but unequal interior angles, producing a stretched rhombic outline that is taller than it is wide. Length-to-width ratios of around 1.6 to 2.0 are most common in cut stones. Facets are arranged in step-cut rows on both crown and pavilion, with the table also a smaller lozenge parallel to the girdle. The corners may be left sharp, in which case they are vulnerable to chipping, or be slightly truncated to produce a six-sided variant. The keel is typically a line rather than a point, running along the long axis.

Historical use

Lozenge-shaped cuts appear in Renaissance and seventeenth-century European jewellery, often as table cuts or simple step cuts in rose-cut diamonds and coloured stones. Their angular geometry suited heraldic and ecclesiastical settings. In the Edwardian and Art Deco periods the cut returned in calibrated form, particularly for diamond accents in geometrical platinum mounts where the elongated rhombus served as a directional element flanking emerald-cut centres or in linear bracelets and brooches.

Modern application

Today the lozenge cut is uncommon as a centre stone but remains in active production as a calibrated side stone, frequently in diamond and ruby. Its angular silhouette is favoured by designers working in the Deco revival idiom and by bespoke makers seeking pointed accents. As a step cut it benefits from high clarity, since the open table reveals inclusions readily; it is most often used in well-formed VS-or-better material. The pointed corners require protective settings, typically V-tip prongs or bezels.

Identification considerations

Because the lozenge belongs to the broader family of fancy step cuts, weight estimation from millimetre measurements requires shape-specific factors rather than the round-brilliant formula. Cutters generally retain about 40 to 45 percent of the rough in a clean lozenge, comparable to other elongated step cuts. The cut should be distinguished from the kite, in which all four sides are unequal, and from the navette or marquise, which has curved rather than straight sides.