If you've looked at the specifications of an automatic watch, you've probably encountered phrases such as "21 jewels," "24 jewels," or "25-jewel automatic movement."
So, what do jewels in a watch mean?
Watch jewels are small, hard components used at particular points inside mechanical movements, commonly where reducing friction and wear is beneficial.
Despite the name, jewel count isn't about making the movement more luxurious.
What Are Watch Jewels?
Mechanical watch movements contain components that move continuously.
Historically and in modern watchmaking, jewel bearings are used at various points within movements.
Synthetic ruby is commonly associated with modern movement jewels.
Why Do Watches Have Jewels?
Jewels can serve as low-friction bearing surfaces within the movement.
They can help reduce wear where certain moving components interact.
This contributes to reliable mechanical operation.
Are Watch Jewels Real Rubies?
Modern watch movements commonly use synthetic jewel materials rather than valuable natural gemstones selected for jewelry.
Their purpose is functional.
You're not buying a 24-jewel watch because it contains 24 expensive jewelry-grade rubies.
What Does 17 Jewels Mean?
A 17-jewel movement uses 17 jewels within its mechanical architecture.
Historically, 17 jewels became associated with fully jeweled basic mechanical movements, although actual movement designs vary.
What Does 21 Jewels Mean?
A 21-jewel movement simply incorporates 21 functional jewels according to its architecture.
The additional jewels may be used at additional movement points depending on the caliber.
What Does 24 Jewels Mean?
Likewise, a 24-jewel movement contains 24 jewels.
The number alone doesn't tell you:
- movement accuracy
- reliability
- power reserve
- finishing quality
You need to evaluate the actual caliber.
What Does 25 Jewels Mean?
Many automatic movements use jewel counts in this general range because automatic winding systems can contain additional moving components.
Again, the specific architecture matters more than the headline number.
Is More Jewels Better?
Not automatically.
This is one of the biggest misconceptions in watch shopping.
A 30-jewel movement isn't automatically better than a 21-jewel movement.
Once the necessary functional points are jeweled, simply increasing the number doesn't guarantee improved performance.
Does Jewel Count Affect Accuracy?
Not directly in the simplistic sense that "more jewels equals more accuracy."
Mechanical accuracy depends on many factors, including:
- movement design
- regulation
- balance system
- manufacturing tolerances
- movement condition
Don't choose a watch based solely on jewel count.
Do Quartz Watches Have Jewels?
Some quartz movements can incorporate jewels, depending on their design.
Jewels aren't exclusive to automatic watches.
However, jewel counts are particularly associated with mechanical-movement specifications.
Why Do Watches Say the Jewel Count on the Movement?
Historically, jewel count became a recognizable way of describing movement construction.
That's why you may see wording such as:
TWENTY-FOUR JEWELS
printed or engraved on a movement.
Is a 24-Jewel Automatic Watch Good?
It can be—but the number 24 doesn't prove it.
Instead, ask:
- Which movement is it?
- What is its accuracy specification?
- What is its power reserve?
- Does it support hacking?
- Does it support hand winding?
- How established is the caliber?
These questions tell you far more.
Jewel Count vs Power Reserve
Jewel count doesn't tell you how long a watch will run.
A movement's power reserve depends on factors such as:
- mainspring capacity
- movement efficiency
- frequency
- architecture
Jewel Count vs Movement Quality
Movement quality should be evaluated as a complete system.
Look beyond marketing numbers.
A proven movement with an appropriate jewel count can be more desirable than an unknown movement advertising a larger number.
Specht & Sohne Automatic Movements
Different Specht & Sohne automatic models may use movements with different jewel counts.
Rather than choosing solely by the number of jewels, compare the complete movement specification and the watch itself.
Final Thoughts
So, what do jewels in a watch mean?
They're primarily functional components used within mechanical movement architecture.
The most important lesson is:
more jewels doesn't automatically mean a better watch.
Movement design, reliability, accuracy, power reserve, and overall construction matter much more than chasing the largest jewel count.