81.17-carat Paraiba leads Bonhams Paris on 29 October
The neon-blue cushion-cut tourmaline carries a €60,000 to €80,000 estimate. Two unheated sapphires over 10 carats, signed Cartier and Chaumet, follow at €40,000 to €60,000 and €45,000 to €65,000.
By The Coloured Stones Desk
What changed
Paris gets a date and a lead stone. Bonhams will sell Fine Jewellery in Paris on 29 October. An 81.17-carat neon-blue Paraiba tourmaline leads at a €60,000 low estimate.
What it means
- If you buy coloured stones at auction: Three of the four lead stones are described as untreated. Read each report.
- If you consign tourmaline: Eighty-one carats is being asked to clear what a 12-carat sapphire clears.
- What this is not: A result, or a trophy sale. The top estimate is €80,000.
Key figures
| Kat Florence Paraiba tourmaline€60,000–80,000, the sale's top estimate | 81.17ct |
|---|---|
| Chaumet sapphire, Sri Lanka, unheated€45,000–65,000 | 12.5ct |
| Cartier “Royal Blue”, Madagascar, untreated€40,000–60,000 | 11.5ct |
| Tourmaline low estimate per caratCC division, 60,000 / 81.17 | €739/ct |
Source: Pre-sale estimates as published by Bonhams on 9 October 2026 for its Paris Fine Jewellery sale of 29 October 2026. Nothing has sold.
One stone carries the sale
Eighty-one carats. The lead lot is a Kat Florence pendant necklace on a cushion-cut natural Paraiba tourmaline of 81.17 carats. Its colour is neon blue and the mount is openwork brilliant-cut diamond.
Sixty to eighty. Bonhams estimates it at €60,000 to €80,000. That is the highest estimate in the catalogue the house has published.
Seven hundred a carat. Attributing the whole low estimate to the stone gives €739 a carat. That is an upper bound on the implied stone price, not a stone price.
| Lot | Stone | Estimate |
|---|---|---|
| Kat Florence pendant necklace | 81.17ct cushion-cut natural Paraiba tourmaline, neon blue | €60,000–80,000 |
| Chaumet Paris ring | 12.5ct octagonal step-cut sapphire, Sri Lanka, no indications of heating | €45,000–65,000 |
| Cartier ring | 11.5ct oval “Royal Blue” sapphire, Madagascar, no indications of treatment | €40,000–60,000 |
| Onyx and diamond ring | Princess-cut diamond centre, onyx surround | €35,000–55,000 |
| Onyx, sapphire and diamond bracelet | Emerald-cut diamonds, calibré-cut sapphire and onyx | €30,000–50,000 |
| Sapphire, pearl and diamond necklace | c.22ct colour-change blue-to-violet sapphire, Sri Lanka, untreated | €16,000–26,000 |
Notes on this table
The per-carat figures are Carat Capital's own divisions off the published low estimates and are shown so they can be checked: 60,000 divided by 81.17 is €739 a carat for the tourmaline, 45,000 divided by 12.5 is €3,600 a carat for the Chaumet sapphire, and 40,000 divided by 11.5 is €3,478 a carat for the Cartier. All three attribute the whole lot estimate to the stone and none deducts anything for the mount, the diamonds or the signature, so each is an upper bound on the implied stone price rather than a stone price. The 22-carat colour-change sapphire is published as approximate and is not divided here.
Untreated is the term
Chaumet, 12.5 carats. An octagonal step-cut Sri Lankan sapphire of 12.5 carats, with no indications of heating, is offered at €45,000 to €65,000 in a Chaumet Paris ring.
Cartier, 11.5 carats. An oval Royal Blue sapphire of Madagascan origin, 11.5 carats, with no indications of treatment, carries €40,000 to €60,000.
Twenty-two, colour-change. A necklace pendant holds an approximately 22-carat Sri Lankan oval that changes blue to violet, untreated, at €16,000 to €26,000.
The rest is signature
Onyx twice over. An onyx and diamond ring carries €35,000 to €55,000. An onyx, sapphire and diamond bracelet follows it in the table, both on geometric Deco construction.
Five names listed. Buccellati, Lacloche, Schlumberger, Zolotas and Lalaounis are named, with a separate section of artist jewellery. No estimates were published for those.
What to watch
- 29 October 2026The sale itself, at Avenue Hoche in Paris. Whether the 81.17-carat tourmaline clears €60,000 is the one number that settles this.
- Before the saleWhether Bonhams publishes the laboratory reports behind the three no-treatment statements. The estimates rest on them and the press release names no laboratory.
- 10 November 2026Christie's Geneva Magnificent Jewels, the next dated coloured-stone and coloured-diamond test on the autumn calendar.
The story so far
Go deeper
What would change this call
A published laboratory report that qualifies any of the three no-treatment statements, which would move the estimates rather than the description. It would also read differently if Bonhams adds a trophy lot before the sale: the catalogue as announced tops out at €80,000, and one late consignment at a higher level would change what this sale is for.
Why Paraiba is priced per stone, not per carat
Paraiba tourmaline trades on colour and on copper content, and its auction record is short. The material was only identified in Brazil in the 1980s and the Mozambican and Nigerian sources that supply most of the large stones arrived later still, so there is no century of comparable results to calibrate against in the way there is for Burmese or Ceylon sapphire. That has two consequences for a reader looking at an estimate. The first is that very large Paraiba is not simply small Paraiba multiplied: a stone this size is a distinct object with its own tiny comparable set, and a house pricing it is choosing a number from a handful of prior sales rather than reading it off a curve. The second is that the mount matters more than usual. A signed pendant on an openwork diamond mount carries value that is not in the tourmaline, and no auction house breaks a lot estimate into stone and setting, so any per-carat figure a reader computes from a published estimate is necessarily an upper bound. Sapphire is the opposite case. A 12.5-carat unheated Ceylon stone sits in a deep, long-documented market where heating status is the single largest value determinant, which is why the treatment line in the catalogue does more work than the weight does.
Method
One primary, read as a press release and not as a result. Bonhams' own press release 41740 was fetched directly this morning (200, 48,487 bytes, saved to newsroom/sources/2026-10-10/desk/bonhams.html) and every figure printed here was greped in the raw bytes first: '29 October 2026' 1 hit, '81.17' 1, '60,000-80,000' 1, '12.5 carats' 1, '45,000-65,000' 1, '11.5 carats' 1, '40,000-60,000' 1, '22 carats' 1, '16,000-26,000' 1, 'Avenue Hoche' 3, 'Kat Florence' 2. The treatment language is the house's own and is quoted in its own terms, 'no indications of heating' and 'no indications of treatment'; no laboratory is named in the release and none is asserted here. ARCHIVE, period rule, both sides named: entity search for 'Bonhams' against website/content/articles.json returns 18 hits, all read. Seventeen are other sales at other houses' dates — Sydney, California, Penzance, three Chanel sales, a Piaget sale, a Garrard egg, a Mouawad parure — and the single hit that mentions Paris at all is 2026-08-08 (a-thirteen-thousand-for-costume.html), a Chanel handbag and fashion sale running 14 to 24 September 2026, a different department, a different catalogue and a different month. 'Kat Florence' 0 hits, 'Avenue Hoche' 0 hits. This paper has never covered a Bonhams Paris Fine Jewellery sale: NEW, no prior period. Filed to the coloured-stones desk rather than auctions because the news is three named stones and their treatment status, following the same call this paper made on 9 October for the Poly Auction sapphire. The per-carat figures are Carat Capital's divisions and are labelled as upper bounds in the table note. Bonhams' quoted specialist comment was read and is not printed: it carries no figure this article needs.