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What Are The Jewels in My Watch For?

Posted on September 10 2020

What Are The Jewels in My Watch For?

Jewel bearings are used in precision instruments where low friction, long life, and dimensional accuracy are important. In watches jewels are used as bearings to help in the frictionless movement of the many tiny parts in your watch. They're set in holes drilled into the movement plate and bridges, and hold the rotating pivots of the movement's gears and wheels. Jewels are differently shaped, depending on their function.

A typical fully jewelled time-only watch without any high complications has 17 jewels: two cap jewels, two pivot jewels and an impulse jewel for the balance wheel, two pivot jewels and two pallet jewels for the pallet fork, and two pivot jewels each for the escape, fourth, third, and centre wheels. If the watch has high-complications such as a perpetual calendar watch, a chronograph (a watch with a stop watch function) or a tourbillon watch will use more jewels.
The only thing that the jewel count can tell you is how many jewels have been used. A higher jewel count in a watch doesn’t necessarily make a watch better, it simply means there are more complications so more bearings are needed to reduce friction between the many components.


The Rolex - 50th Anniversary Submariner for example uses 31 jewels. It is an extremely reliable calibre and the most popular as it maintains perfect accuracy throughout time. The Rolex Kermit features 31 jewels and has 28,800 beats per hour, with 50 hours of power reserve.


Here are watch movements with jewels as shown on our necklaces and cufflinks:

watch movement necklace brass colour watch movement cufflinks with box watch movement necklace in silver

 

Historically, in bearings without jewels, the pivots of the watch's wheels rotate in holes in the plates supporting the movement, causing movement which reduces the life of the watch. So around 1702, jewel bearings were invented and introduced in watches. But they did not become widely used until the mid-19th century. Until the 20th century they were ground from tiny pieces of natural gems such as garnet or quartz or even glass jewels; only top quality watches used sapphire or ruby. Jewels were also made from a rock forming mineral called corundum, one of the hardest substances known which contains traces of iron, titanium, vanadium and chromium. Corundum is the second hardest natural mineral after a diamond.


The expense of natural gemstones in watches certainly played a part keeping watches reserved for the most affluent of people. Naturally occurring mineral corundum is so strong that diamond abrasives were required to cut them, also adding to the cost.


In 1902, a process to create synthetic jewels was invented, making them much cheaper. Today jewels in modern watches feature synthetic corundum, sapphires and rubies. Synthetic corundum is indistinguishable from the naturally occurring kind. Plus, lasers cut these jewel bearings, making watches these days much more affordable.


Here at FIVE:45 we have found and rescued a wide range of long lost watch movements and recreated them into elegant necklaces using solid sterling silver chains. They are without doubt, beautiful and unique pieces of jewellery. We hope that you will let us know which ones you like and what type of chain you prefer as we with a wide variety available, and we will custom design to your taste, style and length. We also have watch movement cufflinks available for sale, more detailed product information is available in our accessories page.

Here is a link to our featured image, one of our favourites named LUNA.

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