Breitling Chronomat Automatic 36 A10320101A1A1: specs and checks

No two of these dials are the same

The dial is mother-of-pearl — nacre, cut from shell — and that makes it the only material in this corpus that is genuinely unique to each individual watch.

A sunburst dial is manufactured to be identical across a production run. Nacre is not. Its iridescence, its banding and the way colour shifts as the watch tilts are properties of the piece of shell it was cut from.

Two consequences, and the first is commercial.

One photograph is not a description. A flat, straight-on image of a mother-of-pearl dial shows one of the many appearances it has, and probably the least interesting one. Shoot it from at least three angles under the same light so the buyer sees how it actually behaves. Otherwise you are inviting a return from someone whose watch does not look like your picture — even though it is exactly the watch you sold them.

The second is about condition.

Nacre cracks. It is a thin layer of natural material, and it is cut through wherever the dial has an aperture or an applied marker. Get a loupe on the date window's edges and around each index, looking for hairlines and for any place the surface has lifted. Damage there cannot be repaired, and it is easy to miss at arm's length because the iridescence distracts the eye.

Read what the sheet does not say

Breitling's page for this reference publishes no crystal line, no bezel line and no case back line.

That is a gap in the documentation, not a gap in the watch. But it is a gap you must not fill from memory or from another Chronomat, because the specifications genuinely differ across the range — the 42 mm chronograph in the same collection lists its crystal simply as sapphire, while other Breitlings here specify cambered sapphire glareproofed on both sides.

The honest way to handle it in a listing is to say so: describe what the manufacturer states, and say that the manufacturer does not state the rest. A dealer who writes "sapphire crystal, sapphire case back" because that is what Breitling usually fits has made a claim nobody can support.

Inspect the actual watch, describe what you see, and label it as your own observation rather than as a factory specification.

Small, thin, and check the numbers twice

Published dimensions: 36 mm in diameter, 9.68 mm thick, with the in-between-lug measurement given as 16.05 mm and the bracelet listed as 20 mm.

Those last two figures do not obviously agree, and that is precisely why you should measure the watch in your hand before ordering any strap or replacement hardware. Quote your own measurement to a buyer, described as your own, rather than either published number.

The rest is straightforward: 10 bars — 100 metres — on a non screw-locked crown with two gaskets, so the rating depends on the crown being fully home and there is no thread to secure it.

The movement is the Breitling 10: self-winding mechanical, 28,800 v.p.h, 25 jewels, approximately 42 hours, with the calendar shown in a dial aperture. Forty-two hours means it stops after two days off the wrist, which is worth a sentence to the buyer.