# What 21, 23 and 24 jewels mean on a watch

Source: https://lumeandbezel.com/blog/watch-jewels-explained
Published: 2026-10-09
Publisher: Lume & Bezel

**Short answer:** Watch jewels are small synthetic rubies used as bearings where moving parts pivot, so steel turns against a hard, smooth stone instead of brass. The number printed on the dial counts how many the movement uses. 21, 23 or 24 jewels are normal counts for modern automatics; the extra jewels mostly support the winding system and calendar, not better timekeeping.

Look at a Seiko 5, a Bulova automatic or an Orient and you will often see a jewel count printed on the dial or caseback: 21 jewels, 23 jewels, 24 jewels. It sounds like a luxury feature, and older advertising treated it as a quality score. This page explains what jewels are, where they sit in a movement, why counts differ between Seiko's 4R35 and 4R36 or between Bulova and Citizen, and why a bigger number does not make a better watch. It is for buyers comparing listings and anyone curious about what the dial is telling them.

## What a jewel does in a watch

A mechanical watch is a set of gears and levers that turn on tiny steel pivots. If those pivots ran directly in holes in the brass plates, friction would be high and the holes would wear oval over time, hurting accuracy. Watchmakers solved this by setting hard stones into the plates as bearings. Steel against polished stone has low friction and very little wear.

Today these stones are synthetic ruby or sapphire, which is the mineral corundum made in a lab. They are cheap to produce and have almost no resale value; their value is functional. The red or pink color you see through a display caseback is the jewels, set at the pivot points of the gear train and escapement.

## Where the jewels sit

Jewels are used where friction and wear matter most. In a simple hand wound watch, about 17 jewels covers the main points, which is why 17 became the traditional count for a so called fully jeweled movement. Automatics add a winding system and often a date or day date mechanism, and makers add jewels there too.

- Gear train: jewels at each end of the wheels that carry power from the mainspring to the escapement.
- Escapement: jewels in the pallet fork (the pallet stones that lock and release the escape wheel) and the impulse jewel on the balance.
- Balance wheel: jewel bearings and cap jewels, often with a shock protection system, since the balance is the most delicate part.
- Automatic winding: jewels in the rotor bearing or reversing wheels on some movements.
- Calendar: some movements add jewels to the date or day mechanism.

## Common jewel counts in listings

These counts come from maker and retailer listings. They show how similar movements end up with slightly different numbers depending on features such as the day wheel or winding system.

| Movement or watch | Jewels | Other listed facts |
| --- | --- | --- |
| Seiko 4R36 (Seiko 5 Sports, some Prospex) | 24 | Day date, hand winding, hacking, about 41 hours reserve |
| Seiko 4R35 (Presage, some Prospex) | 23 | Date, hand winding, hacking, about 41 hours reserve |
| Bulova 8N26 (Sutton automatic) | 21 | 21,600 oscillations per hour, 42 hours reserve |
| Bulova Classic automatics | 21 | Hack feature, 42 hours reserve |
| Citizen 40 mm automatic with integrated bracelet (NJ0156) | 21 | Open case back |
| Caravelle Sea Hunter | 21 | 42 hours reserve |

Jewel counts quoted in listings

Note: Older Seiko 5 models with the 7S26 movement are widely documented as 21 jewels. That movement does not hand wind or hack, which is a bigger practical difference than the jewel count.

## Why more jewels does not mean better

Once a movement has jewels at every point that needs one, adding more does nothing for accuracy or durability. In the mid twentieth century, some makers inflated counts with jewels that served no real purpose, because buyers had learned to read the number as a mark of quality. The industry pushed back, and modern makers generally count only functional jewels.

So a 24 jewel Seiko 4R36 is not better than a 21 jewel Bulova because of three extra stones. The extra jewels reflect its day date and winding layout. What actually separates movements is things like beat rate, power reserve, hacking and hand winding, the quality of the balance spring and how well the movement is adjusted at the factory. Read [how accurate should an automatic watch be](https://lumeandbezel.com/blog/how-accurate-should-an-automatic-watch-be) and [Seiko 5 movements explained](https://lumeandbezel.com/blog/seiko-5-movements-explained) for the specs that matter.

## What to look at instead of the jewel count

If you are shopping for a first automatic, our [best automatic watches under $500](https://lumeandbezel.com/best/best-automatic-watches-under-500) and [best Seiko 5 Sports watches](https://lumeandbezel.com/best/best-seiko-5-sports-watches) list the movement for each pick.

- Accuracy spec: makers publish tolerances in seconds per day. Orient Star listings quote +25 to -15 seconds per day, for example.
- Power reserve: how long the watch runs off the wrist. Listings range from about 40 hours for many Japanese movements to 80 hours for Tissot Powermatic 80 and Hamilton H-10.
- Hand winding and hacking: useful for starting and setting the watch precisely.
- Anti magnetic parts: balance springs such as Nivachron resist the magnetism that commonly makes watches run fast.
- Serviceability: popular movements are easy for most watchmakers to service and get parts for.

## Frequently asked questions

**Are watch jewels real rubies?** They are real corundum, the same mineral as natural ruby, but made synthetically. They are worth very little as stones.

**Is 21 jewels good for an automatic?** Yes. 21 is a normal count for a modern automatic with a date. It tells you the movement is properly jeweled, not that it is better or worse than a 23 or 24 jewel movement.

**What does 'orient crystal 21 jewels' on the dial mean?** It means that Orient model uses a 21 jewel automatic movement. It is a functional count and a normal number for an entry level automatic.

**Does a quartz watch have jewels?** Some do, usually only a few, at points in the gear train that drives the hands. Jewel counts matter much less in quartz because the timekeeping comes from the quartz crystal.

## Gear guides for this topic

- https://lumeandbezel.com/best/best-automatic-watches-under-500
- https://lumeandbezel.com/best/best-seiko-5-sports-watches
- https://lumeandbezel.com/best/best-bulova-automatic-watches

## Sources

- [Wikipedia: Jewel bearing](https://en.wikipedia.org/wiki/Jewel_bearing)