Rubies or synthetic gemstones used in watch movements as bearings to reduce friction and wear.
A complication where the hour is indicated by a jumping hand or disc (usually set underneath the dial) that moves one position on the full hour, every hour.
A feature in which a mechanical watch jumps the seconds hand once per second, similar to an analog quartz watch, instead of traditionally sweeping it to the vibrations of the balance wheel. It’s a difficult and complex mechanism usually reserved for expensive luxury watches. Also known as dead seconds.
