Marina B Cardan — A Hinged Setting That Spins the Stone
Marina B Cardan — A Hinged Setting That Spins the Stone
The signature 360-degree rotating mount of the Marina B maison
The Cardan is the signature setting developed by the Marina B maison: a hinged mount in which a faceted gemstone, held in a frame, rotates freely on a horizontal axis. The wearer can spin the stone through 360 degrees to display either face, or, in the maison's two-stone configurations, to select between contrasting gems. The setting takes its name from the Cardan or universal joint of the Italian polymath Gerolamo Cardano (1501–1576), the same mechanical reference that gives engineering its Cardan shaft. Marina B introduced the setting in the early 1980s, and the Cardan has been the maison's most-imitated and most-attempted design ever since.
Mechanical principle
The Cardan setting consists of a frame — typically rectangular, oval, or shield-shaped, in 18-karat gold — that holds the gemstone on two opposing pivot points along the centreline of the stone's table. The pivot points are precision-machined to allow the stone to rotate smoothly while maintaining position when not actively turned. The frame, in turn, is mounted to the ring shank, pendant bail, or earring fitting in a manner that allows the setting to be worn either with the stone displayed face-up or face-down.
The technical achievement is in the precision of the pivots: too tight and the stone resists rotation; too loose and the stone moves in ways that are not under the wearer's control. The maison's workshop has refined the mechanism over four decades to achieve a balance of ease of rotation and positional stability.
Two-stone configurations
The most distinctive Cardan pieces are two-stone configurations in which the gem is double-sided — a different colour or different cutting on each face — so that the wearer can rotate to display either side. Common combinations include cabochon and faceted faces of the same colour (cabochon ruby on one side, faceted ruby on the other), contrasting colours (sapphire and ruby; emerald and citrine), and stone-and-pavé combinations (a single coloured stone on one side, pavé diamond on the other). The two-sided format is technically demanding because the stone must be cut and polished on both faces.
Application across the line
The Cardan setting has been applied across rings, pendants, earrings, and brooches in the Marina B production. Rings are the most common Cardan format; the setting is well-suited to a ring profile because the wearer can rotate the stone with thumb and forefinger while the ring is on the hand. Pendant Cardans are typically worn with the stone visible on one face, with the alternate face available when the pendant is reversed or rotated by hand. Earring Cardans are less common because the rotation is less easily managed in wear.
Position in the market
The Cardan setting is a recognisable Marina B signature and Cardan-set pieces command premium pricing in the secondary market. At auction, Cardan rings from the 1980s and 1990s typically trade in the four- to five-figure range depending on stone size and quality, with major two-stone configurations and high-quality coloured-stone Cardans reaching six-figure prices. Pieces with documented Marina Bulgari-era manufacture (pre-1991, before the first sale of the maison) generally trade at modest premium over later production.
Identification
Authenticated Cardan pieces carry the Marina B maison hallmark (Marina B with year), the gold karat mark (typically 750 for 18-karat), and the maker's mark of the workshop. The mechanical action of the setting is a useful authentication point — well-made Cardan settings rotate smoothly with light pressure and hold position when released. Modern reproductions and unrelated rotating-setting designs from other makers do not generally match the precision of Marina B workshop production.
In the trade
For dealers and collectors, the Cardan is one of the recognisable late-20th-century setting innovations and a piece that distinguishes the Marina B maison from its contemporaries. The maison's continued production of Cardan pieces under the post-2012 ownership has kept the setting current; original Marina Bulgari-era pieces command modest provenance premium. The standard reference for attribution is the maison archive in Geneva.