If you've searched "what do jewels in a watch do," "17 jewels vs 21 jewels," "what are watch movement jewels," or "how many jewels should an automatic watch have," you may have wondered why mechanical watch specifications often mention a jewel count.
The jewels inside an automatic or mechanical watch aren't primarily decorative. They're functional components used within the movement to help reduce friction at important contact points.
Understanding watch movement jewels can make automatic watch specifications much easier to interpret.
What Are Watch Jewels?
Watch jewels are small synthetic stones used at selected points inside a mechanical movement.
They are commonly made from synthetic ruby or sapphire and may be positioned where moving components interact.
Their purpose can include helping to:
- reduce friction
- reduce wear
- support moving components
- improve long-term movement operation
They are extremely small but play an important role in mechanical watchmaking.
Why Do Mechanical Watches Need Jewels?
An automatic watch contains many constantly moving components.
These can include:
- gears
- pivots
- balance components
- escapement parts
- winding-system components
Metal rubbing directly against metal can create friction and wear.
Jewels provide a hard, smooth surface at selected friction points.
Does a Higher Jewel Count Mean a Better Watch?
Not necessarily.
This is one of the most common misconceptions when comparing automatic watch movements.
A movement with 24 jewels isn't automatically superior to one with 21 jewels.
The appropriate number depends on:
- movement architecture
- complications
- automatic winding system
- movement design
Extra jewels only provide value when the movement actually requires them.
What Does 17 Jewels Mean?
Historically, 17 jewels became a common configuration for many basic mechanical movements.
A traditional movement may use jewels around important areas such as:
- gear-train pivots
- escapement
- balance assembly
The exact layout depends on the caliber.
17 Jewels vs 21 Jewels
The 17 jewels vs 21 jewels comparison sounds important, but jewel count alone tells you relatively little about overall quality.
Additional jewels may be used for components associated with:
- automatic winding
- additional complications
- movement architecture
Rather than choosing a watch based on jewel count, examine the complete movement.
Are Watch Jewels Real Rubies?
Modern movement jewels are generally synthetic.
They're manufactured specifically to provide consistent properties for mechanical applications.
Their value comes from their function—not rarity.
Can You See the Jewels?
If your automatic watch has an exhibition caseback, you may be able to see some red or pink jewel bearings inside the movement.
Other jewels may be hidden underneath movement components.
Do Quartz Watches Have Jewels?
Some quartz movements can contain jewels, although the architecture and requirements differ from traditional mechanical watches.
Jewel counts are generally discussed much more frequently in the context of mechanical and automatic movements.
What Matters More Than Jewel Count?
When evaluating a movement, prioritize:
- reliability
- accuracy specification
- power reserve
- hacking capability
- manual winding
- serviceability
- movement reputation
A watch with fewer jewels can still be an excellent movement.
Specht & Sohne Automatic Watches
Specht & Sohne automatic watches use mechanical movements selected according to the design and functionality of each model.
When comparing models, checking the entire movement specification gives you much more useful information than simply comparing jewel counts.
Final Thoughts
Watch jewels are functional components designed to help mechanical movements operate efficiently at important friction points.
But remember:
More jewels don't automatically mean a better watch.
Movement design, reliability, construction, and overall performance matter far more than the number alone.