A red gemstone the ruby belongs to the corundum mineral family. Rubies are known as “jewels” in watchmaking and used at certain points in the movement to reduce friction.

By reducing friction they also reduce wear and therefore lengthen the life of the watch.

They were first used in a watch mechanism in 1704 by Nicolas Fatio de Duillier. Real rubies are no longer used in watches today but synthetic ones.

RotorSapphire Crystal