That’s a cabochon…
You see that smooth and shiny rounded gemstone with no facets? It’s a cabochon. Here’s a definition from GemSelect:
A cabochon is a stone that is cut with a highly polished rounded or convex top with no faceting and a flat or slightly domed base. A cabochon may be cut in any shape, though oval is by far the most common. The term comes from the French caboche, meaning knob or small dome.
We often refer to a cabochon-cut stone in a jewelry setting, but cabochons are not really cut – they’re shaped, smoothed and polished. Despite the technology and skill available for cutting faceted gemstones, some stones are always cut as cabochons, usually for a reason such as displaying special properties better – as in stones with a ‘star’ (asterism).
The two sapphire cabochons below, set in rings, have no special qualities that require their smooth domes, but they do look wonderful!!
Cabochon sapphire rings
For sale online at Sparkle n Dazzle Co, this cabochon sapphire’s rich colour is deeply satisfying. It’s Edwardian, with the high round 6K cabochon flanked with trapezoid and bullet cut diamonds set in filigree platinum, with milgrain edging. Price is $24,950.00.
Below is a 1920’s sapphire sugarloaf cabochon ring – one of the talking points at a 2015 Bonhams auction in London. The sapphire is a cool cornflower blue, shaped ino a sugarloaf cabochon – smooth, but with a raised, rounded ridge.
It’s a Kashmiri sapphire of just over 21 karats – remarkable because of its size and because the Kashmir mines are now closed and produced very limited amounts of rough stone in its last years. Kashmiri sapphires are highly prized because of their quality and colour.
So perhaps it was no surprise that this ring sold for three times its estimate, reaching a price of $440,000.