It has been a tradition, being followed since the 1700s, to use hard stones like sapphire or ruby for the jewel bearing in a mechanical automatic watch. Before this, they were using metal bearings, and friction caused by metal rubbing against metal caused inaccuracies in timekeeping. Replacing the metals with jewels solved the problem of friction, while also improving the lifespan and accuracy of the white watch. The reason the jewel bearings increased the lifespan of the ceramic watch, is that they didn’t make the metal parts of a mechanical watch wear down as quickly as the metal bearings did.
In the year of 1902, Auguste Verneuil came up with a way to combine sapphire and ruby. Before this occurred, not every watch-maker could afford jewel bearings, as it was too costly for them to use sapphire, ruby, and other precious stones. So incorporating the synthesis method cut down on the price, allowing every watch-maker to be able to use jewel bearings in their models of the mechanical white ceramic watch.
Come the 20th century, however, it became startlingly difficult to improve on the hard task of creating and putting final touches on the bearings and movements of the models and types of the mechanical watch that were being created. This resulted in watch-makers eventually deciding to just give up on that and just use the precious stones in their watches in places where they weren’t necessary to make the watch work any better, so the jewels bearings became no more than accessories.
Until the practice of using precious stones and other jewels in a mechanical watch where the said jewel wasn’t needed, was banned by the ISO (International Standardization Organization), the jewels were being commonly used to beauty a mechanical watch a lot more than to improve the functionality of the watch itself.
