A beginner watch enthusiast may describe watch jewels as the diamonds encrusted on a Rolex… We’ve all started our watch-collecting journey somewhere.
However, while precious gems have their place in watch décor, jewels play a much larger role in a timepiece than purely aesthetics.
So, what exactly do we mean when we mention watch jewels or jewel bearings? What’s the difference between a watch with, say, 17 and 21 jewels? Does having more mean you have a better or more expensive watch? Read on to find out!
What are Watch Jewels?
Watch jewels are synthetic rubies or sapphires used to decrease friction in a mechanical watch movement. They are tiny, but essential components that contribute to the durability, accuracy, and precision of a watch.
What Are Watch Jewels Used For?
A watch is made up of many different moving parts. These parts can experience significant wear and tear over time, negatively impacting performance and longevity.
This is where jewel bearings come in.
Jewels are a part of a mechanical watch movement that is used to decrease friction between parts.
What are Watch Jewels Made Out Of?
Jewels are typically synthetic rubies or sapphires (collectively known as corundum crystals).
With a hardness of 9 out of 10 on Moh’s Hardness Scale, corundums are a very durable mineral, only beaten to the punch by diamonds. It is also much harder than metal and will not degrade as quickly. Corundum can withstand very high temperatures without deterioration and degradation and is resistant to acid. Corundum’s crystalline structure allows it to be polished to a very smooth surface.
When these materials are used as jewels in watch movements, the amount of friction is significantly decreased, and allow the parts in a watch movement to slide much more easily. This results in higher efficiency and less wear and tear inflicted on the moving parts in a movement.
What Kind of Watches Use Jewels?
Now, you may be wondering if all watches use jewel bearings. There are three main types of movement: quartz, automatic, and manual.
Mechanical, Hand-Wound Movements
Manual watches are hand-wound. They generally use between 17 and 21 jewel bearings to decrease friction between watch parts, preventing them from grinding against each other and wearing down over time.
Automatic watches are wound up using the kinetic energy of their wearer’s wrist. They do not need to be manually wound, unlike their manual counterparts, although some automatic watches have the ability to wind manually also.
Due to their added complexity, automatic watches typically have even more jewels (17 – 27), due to the need to efficiently transfer energy from the wearer’s wrist.
It is important to keep in mind, though, that these jewel numbers are averages. The higher the number of complications in a movement, the more jewels will be needed. The world’s most complicated watch, the Vacheron Constantin 57260, was revealed to have 242 jewels!
Do Quartz Watchese Need Jewels?
Quartz watches most often do not use or need jewels to run. Quartz watches are powered by electricity, specifically, an electric oscillator modulated by the quartz crystal. They have moving parts that can justify the use of jewel bearings.
However, their movements do not have as many gears. Further, the gears that are there only make small movements, remaining motionless most of the time. As a result, it is common to find a high-quality quartz timepiece without a jewel.
In a nutshell, a quartz watch does not need jewels to function.
Types of Watch Jewels
There are four main types of watch jewels:
These are rectangular and are found on either arm of a pallet fork. They are split into two types, “entry and exit.” They take turns transferring power to the balance by locking the gear train and they always work in pairs.
Hole jewels are somewhat ‘doughnut shaped’ and are identified by a hole that is cut right into the middle of the jewel.
They are typically used to reduce friction at a point where there is circular movement at a cylindrical or conical pivot. They may sometimes be paired with a cap jewel to make a pivot bearing, which is a part that functions in fixed, vertical support.
This jewel is used to reduce the movement of the balance staff. It always occurs with a hole jewel. It contributes to greater accuracy and performance than a hole jewel on its own. It may also be used to aid in shock protection in case the watch is dropped or hit by some force.
Roller jewels connect the escape wheel and pallets in a watch’s movement. They are usually found inside the pallet fork of a movement.
How Many Jewels Should a Watch Have?
Mechanical watches typically have 17 or 21 jewels. Automatic; self-winding watches sometimes have as many as 27 jewels or more, depending on their complexity.
So what’s the better option? A 17 jewel movement, or a 21 jewel movement? That, in essence, depends on your budgets. A good quality, time-only watch without tons of complications will often use 17 jewel. At the same time, the 4 additional jewels in more high-end watches will help to reduce positional errors, and deviations over time.
In standard watches, you can expect the following:
- 7 jewels in the escapement and balance.
- 8 hole jewels, used to reduce friction at the quick-moving parts of the gear train.
- 2 jewels set into the center wheel.
- 2-4 cap jewels, typically found on the escape wheel and the pallet.
Are More Jewels in a Watch Better?
A watch can have many, many jewels, but does that necessarily make the watch better?
No, having more jewels does not always make a better watch.
While it’s true that sometimes more expensive and more complicated, watches will use jewels, it’s not the quantity of jewels that makes the difference; rather, the additional complexity and interest of the watch to begin wtih.
Watch With The Most Jewels
For example, the Vacheron Constantin Ref. 57260, the “World’s Most Complicated Watch“, according to Forbes, has a whopping 242 jewels. With 57 functions, including an entire sky chart, it makes sense this specific model would require so many jewels to operate smoothly.
Watch With Useless Jewels
However, some watches, such as the vintage Waltham 100 jewels automatic men’s watch, have an excessive amount of jewels for no reason except as a marketing ploy. 83 of the jewels in Waltham’s timepiece are non-functional. This makes the timepiece a standard, seventeen-jewel movement. A good, dependable timepiece, but nothing except bragging rights are to be gained from the additional corundum
Benefits of Having More Jewels
So, what exactly is the point of having more watch jewels?.
Watches with more jewels will typically last longer without needing a service because of their reduced points of friction. Metal rubbing against metal can cause damage over time, so having a smooth surface for a part to slide across is essential to a long-lasting mechanical movement that you can pass down for generations to come.
Of course, the jewels need to be lubricated appropriately with the right synthetic oils, usually done in a watch service, to be able to keep the watch running smoothly.
Smooth Handling of Complications
Each additional complication in a watch movement typically requires additional mechanical parts and points of friction. Having more jewels in a watch with more complications, such as the previously mentioned Vacheron Constantin 57260, allows the watch’s multitude of complications to run more smoothly and efficiently.
How Much Do Watch Jewels Cost?
Synthetic jewels are cheap and easy to manufacture. This means these bearings are no longer as expensive as they once were when they were cut from natural stones. A single jewel will cost at least $5 and, at most, $20. So don’t worry; no one will be robbing you for the rubies in your watches (and you won’t be able to sell them either, at least not for much).
Since they’ve become so affordable, some watch manufacturers, such as Seiko, have begun integrating their own manufactured jewels, even in their affordable timepieces.
On the flip side, you may expect luxury brands such as Rolex and Patek Phillipe to use natural corundum for their jewels, but that is not the case. For the most part, they also make use of synthetic corundum.
Jewels are much easier and cheaper to make and is manufactured for that specific purpose, making it a convenient choice. Real corundum would need to be mined, cut and set, making the watch much more expensive, unncessarily.
As you can see, jewels are a vital part of watches and can be the difference between a cheap timepiece and a high-end one. However, it’s evident that having more jewels does not always equate to a better watch.
It is also important to note that some watches have corundum crystals that are not functional at all, and are simply used for marketing.
In some cases, a high jewel number simply indicates increased complexity and not increased quality. So, the next time you purchase a watch, consider your needs instead of simply going for the model with a higher number of rubies.