Cartier 11.5-ct sapphire ring makes €205,400 at Bonhams Paris
Bonhams says the Madagascan stone shows no indications of treatment; the ring made 3.4 times its high estimate on 29 October. A Cartier rose brooch made €83,800 against €15,000 to €20,000.
By Carat Capital
What changed
The sapphire led. Bonhams says a Cartier ring with an 11.5-carat Madagascan sapphire was the top lot of its Paris sale on 29 October. It made €205,400.
What it means
- If you buy sapphire: Two sapphires described with no indications of treatment made 3.4 and 1.8 times their high estimates.
- If you consign signed jewels: Five of the six named lots beat their high estimates; the tourmaline did not.
- What this is not: A sale total. Bonhams gives none, nor a share of lots sold.
Key figures
| Cartier sapphire ringestimate €40,000–60,000 | €205,400 |
|---|---|
| Against high estimateCC division, 205,400/60,000 | 3.4× |
| Cartier rose broochc.1940, estimate €15,000–20,000 | €83,800 |
| Paraiba-type pendantinside €60,000–80,000 | €64,600 |
Source: Bonhams press release, 30 October 2026, for its Paris Fine Jewellery sale of 29 October 2026. Ratios are Carat Capital's division.
Sapphires without treatment indications led.
No treatment indicated. Bonhams describes the oval 11.5-carat 'Royal Blue' stone as Madagascan, with no indications of treatment. Its estimate was €40,000 to €60,000.
Sri Lanka followed. A necklace with a colour-change Sri Lankan sapphire of about 22 carats made €46,680, 1.8 times its high estimate. Bonhams describes that stone the same way.
| Lot | Result, € | Estimate, € | Result ÷ high |
|---|---|---|---|
| Cartier sapphire ring, 11.5 ct | 205,400 | 40,000–60,000 | 3.4× |
| Cartier rose brooch, c.1940 | 83,800 | 15,000–20,000 | 4.2× |
| Kat Florence tourmaline pendant, 81.17 ct | 64,600 | 60,000–80,000 | 0.8× |
| Diamond ring, 4.23 ct | 46,680 | 23,000–33,000 | 1.4× |
| Sapphire, pearl and diamond necklace | 46,680 | 16,000–26,000 | 1.8× |
| Lacloche Frères ruby necklace, c.1912 | 32,500 | 6,000–10,000 | 3.3× |
Results as Bonhams states them; the release does not say whether they include buyer's premium. The last column is Carat Capital's division, rounded.
The preview's lead sold inside estimate.
Paraiba within range. The 81.17-carat Paraiba-type tourmaline pendant led Carat Capital's 10 October preview. It made €64,600, inside its €60,000 to €80,000 estimate.
Chaumet not listed. The preview's 12.5-carat Chaumet sapphire, estimated at €45,000 to €65,000, is not among the results Bonhams names.
Older signed pieces beat estimates.
Brooch at 4.2 times. A Cartier rose brooch in ruby, emerald and diamond, from about 1940, made €83,800. It came from the collection of the milliner Madame Paulette.
Lacloche well above. A Lacloche Frères ruby and diamond necklace from about 1912 made €32,500 against €6,000 to €10,000.
What to watch
- 11 November 2026Sotheby's Geneva, where a 69.44-carat Ceylon sapphire listed as unheated is estimated at CHF 580,000 to 750,000. The test: a result above the high estimate.
The story so far
Go deeper
What would change this call
A full lot list showing many lots unsold or below estimate would change this call. Bonhams names only six results.
Estimate against result
An estimate is the house's pre-sale range. Dividing the result by the high estimate shows how far bidding ran past it; a figure under 1.0 means the lot sold inside or below the range.
Method
Bonhams, press release 41838, header 'Fine Jewellery, Paris 29 Oct 2026', listed in the Bonhams press RSS with pubDate 30 October 2026 11:16 UTC (the Bureau's capture, 899,995 bytes). Fetched by the Editor on 31 October 2026, door.py 200, 44,470 bytes (newsroom/sources/2026-10-31/desk/41838.html; the Bureau's count was the same). Tag-stripped text: 'The top lot was a Cartier sapphire and diamond ring', 'weighing 11.5 carats with no indications of treatment', '€205,400', '€40,000–60,000', '€83,800', '€15,000–20,000', 'Madame Paulette', '81.17 carats', '€64,600', '€60,000–80,000', '4.23 carats', '€46,680' (two lots), '€23,000-33,000', '€16,000-26,000', 'approximately 22 carats, with no indications of any treatment', '€32,500', '€6,000-10,000' each read in its sentence. The release says the sapphire made 'five times its pre-sale estimate'; that is the low-estimate ratio (205,400 / 40,000 = 5.1) and is not used. Arithmetic, ours: 205,400 / 60,000 = 3.42; 83,800 / 20,000 = 4.19; 64,600 / 80,000 = 0.81; 46,680 / 33,000 = 1.41; 46,680 / 26,000 = 1.80; 32,500 / 10,000 = 3.25, shown as 3.3. The release gives no sale total, no sell-through and no premium basis, and names no laboratory report; 'untreated' and 'no indications of treatment' are the house's descriptions. The Chaumet 12.5-carat sapphire (estimate €45,000 to €65,000 in the 10 October preview) is not in the release: no result for it is printed. One quotation from a Bonhams specialist is in the release and is not used. Source verbs: the house says 'achieved', 'realised', 'exceeded'; this page says made and beat. ARCHIVE, by entity: 'Bonhams' 20 rows in website/content/articles.json (the Bureau, 31 Oct); the 10 October preview, eighty-one-carats-of-paraiba-in-paris, opened and read. Ours: preview of the 29 October sale, 10 October | new: its results: ADVANCED.
Sources
- Bonhams, press release, Fine Jewellery, Paris, 29 October 2026 30 October 2026