What Do Jewels Mean in Watch Movement?

In every mechanical watch, hundreds of microscopic parts work together to measure time with astonishing precision. Behind the ticking hands lies a complex network of gears, pivots, and levers—all moving in harmony. But what allows these parts to move smoothly without wearing each other down?

The answer lies in something deceptively simple: jewels. You’ll often see terms like “17 jewels” or “23 jewels” engraved on a watch movement. These numbers aren’t decorative or symbolic. They refer to the small synthetic stones that keep a watch’s inner mechanics running efficiently.

Understanding what jewels do—and what “23 jewels” really means—reveals an essential part of mechanical watchmaking. It’s a story about friction, endurance, and the science of precision.

What Are Jewels in a Watch Movement?

In watchmaking, jewels are tiny synthetic stones used as bearings inside the movement. Their purpose is simple but critical: they reduce friction where metal parts move against each other.

A mechanical or automatic watch contains dozens of gears and wheels that rotate thousands of times each day. Without protection, the constant metal-on-metal contact would create heat, wear down components, and affect timekeeping accuracy.

To prevent this, watchmakers place synthetic jewels at the points of highest friction—usually where pivots and wheels rotate. These jewels provide a hard, smooth surface that minimizes resistance and wear.

So when a watch includes “23 jewels,” it means that 23 of these tiny stones are strategically placed throughout the movement to ensure long-term precision and efficiency.

Why Synthetic Rubies Are Used

Despite the name, the jewels inside a watch aren’t natural gems. They’re lab-grown rubies or sapphires that have identical hardness and clarity to their natural counterparts.

Synthetic rubies are ideal for watchmaking because they’re extremely hard, measuring 9 on the Mohs scale, just below diamond. This hardness allows them to resist scratches and deformation, even after decades of motion.

They’re also perfectly smooth, which is essential for reducing friction. When a polished ruby supports a steel pivot, the contact is almost frictionless. This small detail makes a huge difference in how a watch performs over time.

So while the word “jewel” might sound ornamental, these stones are purely functional—a triumph of precision engineering rather than decoration.

The Function of Jewels in a Watch

A watch movement functions like a miniature engine. Every part must move with exact precision to keep accurate time. But where there’s movement, there’s friction—and friction is the enemy of precision.

Jewels are used to support rotating parts and reduce friction in critical areas such as:

• The balance wheel, which regulates timekeeping
• The escapement, which releases energy to the gear train in controlled pulses
• The gear train, which transfers power from the mainspring to the hands

By acting as low-friction bearings, jewels help the movement run smoothly, prevent premature wear, and maintain stable performance across years of use.

Without jewels, the delicate pivots and axles inside the movement would grind down quickly, throwing off accuracy or stopping the watch altogether.

How Many Jewels Does a Watch Need?

The number of jewels in a watch depends on the complexity of its movement.

A simple manual-wind mechanical watch might use 15 to 17 jewels, which is enough to cover all the essential friction points in the gear train and escapement.

An automatic watch, which has additional parts for self-winding, usually includes 21 to 25 jewels.

A movement marked “23 jewels” generally means it’s an automatic mechanism with a full set of bearings for both timekeeping and winding.

More complicated watches, such as chronographs or those with calendars, may contain 30 or more jewels to support extra gears and levers.

However, jewel count alone doesn’t determine quality. Once every functional contact point is covered, adding more jewels doesn’t necessarily improve performance.

What Does 23 Jewels Mean in a Watch Movement?

Seeing “23 jewels” on a watch movement indicates that the mechanism contains 23 friction-reducing bearings.

This jewel count is typical for a fully jeweled automatic movement, meaning every crucial moving part, including the self-winding rotor system, is protected by synthetic ruby bearings.

A 23-jewel movement is generally considered a sign of engineering completeness rather than excess. It reflects a movement that’s been optimized for durability and long-term accuracy, not just adorned with unnecessary parts.

In short, “23 jewels” suggests a well-balanced movement with efficient energy transfer and minimal internal wear.

Are More Jewels Always Better?

Not always.

It’s easy to assume that a higher jewel count means a better watch, but that’s a misconception. Once all the essential friction points have been jeweled, additional stones don’t add real value.

For example, a 17-jewel manual movement and a 23-jewel automatic movement can perform equally well within their respective designs. The difference simply reflects the number of moving components that require protection.

In the past, some manufacturers added non-functional jewels purely for marketing appeal. So while jewel count matters, it’s best viewed as part of a bigger picture—one that includes movement design, finishing, and performance.

Jewels and Watch Accuracy

Jewels help maintain accuracy, but they don’t directly improve it.

The precision of a watch depends on how well the movement is designed, assembled, and regulated. Jewels ensure that the moving parts can operate consistently by minimizing friction, which in turn helps the mechanism maintain stable timing.

A watch with fewer jewels can still be accurate if it’s well-made. The jewels simply protect that accuracy over time by extending the life of the movement’s key components.

Think of them as the smooth pathways that allow the rest of the mechanism to do its job efficiently.

Placement of Jewels in the Movement

Each jewel in a watch has a specific purpose. They’re carefully positioned at points where friction is greatest and precision matters most.

The main types include:

• Hole jewels, which support gear pivots and allow them to rotate freely
• Cap jewels, which sit above hole jewels to hold lubrication and prevent vertical shift
• Pallet jewels, used in the escapement to control how energy is released from the mainspring

Together, these jewels form the invisible infrastructure that keeps the movement running smoothly, tick after tick.

How Jewels Improve Durability

Jewels play a crucial role in the longevity of a watch.

Because rubies are nearly indestructible, they protect the most delicate parts of the movement from wear. Over decades, they help preserve the tight tolerances required for accurate timekeeping.

Without jewels, the constant friction of metal parts would eventually cause deformation, leading to erratic performance or complete failure.

This is why even the most basic mechanical watches contain at least a few jewels—they’re indispensable to the watch’s long-term health.

Jewels in Quartz Movements

Quartz watches also use jewels, though far fewer than mechanical ones.

Because their internal parts move less, a quartz movement may only need 1 to 5 jewels to reduce friction in key areas like the gear train or stepping motor.

In quartz watches, jewels serve the same purpose—ensuring durability and smooth operation—but their role is much smaller because the movement itself is simpler and powered by electricity rather than stored mechanical energy.

The Evolution of Jewel Bearings in Watchmaking

The use of jewels in timepieces dates back to the early 1700s, when watchmakers discovered that gemstone bearings drastically reduced wear in pocket watches.

Originally, natural stones were used, which made jeweled movements rare and expensive. The invention of synthetic rubies in the early 20th century changed everything.

For the first time, watchmakers could produce precise, uniform jewel bearings in large quantities. This innovation made mechanical watches more reliable, affordable, and consistent.

Today, synthetic jewels are a standard part of nearly every mechanical movement—a quiet revolution that reshaped modern horology.

Evaluating Jewel Count When Buying a Watch

When assessing a watch, jewel count can give you general insight into its construction, but it should never be the sole factor.

A movement with 17 to 23 jewels typically indicates a fully jeweled design capable of long-term reliability. Anything beyond that usually signals additional complications rather than higher quality.

Instead of focusing solely on the number, consider the watch’s movement architecture, accuracy, and finishing. Those elements matter far more to performance and longevity.

If you’re interested in mechanical watches that pair traditional craftsmanship with modern reliability, you can explore thoughtfully designed timepieces at NTN’s official website, where precision and durability come together seamlessly.

Caring for a Jeweled Movement

Even with jewels, a mechanical movement still benefits from regular maintenance.

Lubricants can dry out or attract dust over time, which affects the smooth interaction between pivots and jewel bearings. Having your watch serviced every few years keeps those interfaces clean and efficient.

It’s also wise to avoid strong shocks, magnets, and extreme temperatures, all of which can disrupt the delicate balance within the movement. With proper care, the jewels—and the entire mechanism—can last for generations.

Final Thoughts

So, what do jewels mean in a watch movement—and what does 23 jewels mean in a watch movement?

They’re the small synthetic rubies that reduce friction, protect the pivots and gears, and ensure the watch runs smoothly for years.

A 23-jewel watch typically represents a complete, well-engineered automatic movement—one designed for efficiency, durability, and reliable performance.

But the jewel count alone doesn’t define quality. What truly matters is how those jewels are used, and the craftsmanship behind the movement that houses them.

In the world of mechanical watches, jewels aren’t just tiny stones; they’re the foundation of precision—silent, enduring, and essential to every tick of time.