Balance

Moving watch part, usually circular, oscillating about its axis of rotation. The hairspring coupled to it makes it swing to and fro, dividing time into exactly equal parts. Each of the to-and-fro movements of the balance is called an oscillation.

Bezel

The surface ring on the watch that surrounds the crystal and holds it in place. On many sports watches, bezels rotate with a ratcheting movement. Rotating bezels may be uni- or bi-directional. Unidirectional bezels are traditionally found in diving watches, and are constructed as such to prevent accidental "increasing" of the alloted dive time. If the bezel is accidentally moved, it will only be to reduce the dive time.

Brilliant

The term brilliant is often used interchangeably with the mineral diamond. However, the "brilliant" designation may only be applied to a circular cut natural diamond with at least 32 crown facets and a table and at least 24 pavilion facets and a culet.

Brilliance

The total amount of white light, both external and internal, returned from the diamond to the eye of the observer.