Why Rubies Are Essential in Watchmaking: History and Applications

You can often see the word “ruby” on the dial of your watch, but what does it mean? Is it a guarantee of quality or a controlled designation of origin? Let’s discover together the rubies that are hidden in your watches.

The story behind these rubies

In watchmaking, rubies are used to limit friction on certain components. These components were once in "metal against metal" friction and wore out quickly. The efficiency of the mechanism therefore decreased drastically because of this friction.

Rubies were then used to limit this friction and thus reduce the wear of watches and increase the efficiency of the mechanisms. The technical process for drilling these rubies was invented at the beginning of the 18th century in England by Nicolas Fatio de Duillier.

Initially, these rubies were natural. They have been gradually replaced by synthetic rubies since the beginning of the 20th century thanks to the French chemist Auguste Victor Louis Verneuil. These synthetic rubies have a better constitution, no defects and are above all much less expensive than natural rubies.

Ruby = Quality?

Rubies are indeed a guarantee of quality, at least they used to be. Today a ruby ​​is essential in a watch, even the most affordable mechanical movements have them. Be careful, this is not the case for quartz movements, rubies are only found on high-end movements from major brands. The explanation behind all this is simply linked to production costs. The cogs of these movements are mostly made of plastic and using rubies would be useless.

How many rubies are in my watch?

In a watch, there are usually between 15 and 25 jewels. However, if you have a model with a complication, there will be more jewels in your movement. Indeed, more components means more jewels.
It is sometimes possible to see 100 rubies on a single watch but do not be fooled, these are watches with 15 rubies in the mechanism and 85 distributed elsewhere. In the photo below the rubies implanted everywhere are not even drilled and are placed for the aesthetic side.

Conclusion

To conclude, the rubies that serve to limit the wear of your movements are no longer a guarantee of quality but have become a watchmaking standard. In the majority of watches, there are about fifteen of them and this number can rise to thirty depending on the complications.

SOURCES:

• Spiral pendulum photo: Wikipedia

• Raw ruby ​​photo: Drouot

• Photo shows 100 rubies : Diving Watch Discussion Forum