A cabochon is a gemstone that has been shaped and polished to a smooth dome rather than cut into facets. The form is ancient, predating faceted cutting by centuries, and it remains in use because certain stones and certain aesthetic purposes suit it better than any faceted alternative.
Why Some Stones Are Cut as Cabochons
Stones with optical phenomena that only appear when the gem is viewed as a dome are cut this way as a matter of necessity. Star rubies and star sapphires display their asterism (the six-rayed star produced by needle-like inclusions) only when cut with the dome centred correctly over the stone's axis. Cat's eye stones similarly show their effect only in cabochon form.
Beyond these functional reasons, opaque and translucent stones where faceting adds little visual benefit are frequently cut as cabochons: turquoise, lapis lazuli, malachite, and coral appear throughout Cartier's coloured stone work in this form. Even transparent stones are sometimes cut as cabochons when the intention is to emphasise colour saturation and a diffuse, glowing quality rather than the flashing brilliance of a faceted gem.
In Cartier's Watches
The sapphire cabochon crown appears throughout Cartier's watch output as a consistent signature detail. It features on the Baignoire, the Crash, and many of the other shaped models from the London and Paris workshops. The winding crown is a small functional component, but the sapphire cabochon set into it connects even a working part of the watch to the broader material language of the house.
In Jewellery and Indian Commissions
In Cartier's Tutti Frutti and Indian-style pieces, carved coloured stones frequently take a form related to the cabochon tradition, where the stone's colour and surface are the point rather than any play of light through facets. Serti mystérieux settings, by contrast, work with faceted stones, and the contrast between the two approaches reflects different design intentions entirely.
The cabochon's place in Cartier's work spans functional detail and central design element, from the crown of a wristwatch to the dominant stone in a major commission.
Sources
- Francesca Cartier Brickell, The Cartiers (Ballantine Books, 2019), ch. 5 (“Stones Paris: Early 1920s”) and ch. 11 (“The End of an Era, 1957–1974”)
- Hans Nadelhoffer, Cartier: Jewelers Extraordinary (Thames and Hudson, 1984; revised 2007), pp. 144, 165 et al.
- Wikipedia: Cabochon
