Atomic clock

A caesium clock draws on the hypothesis of stable atomic properties, in particular the frequency of radiation corresponding to the transitions between two energy levels. The atomic frequency...

Back

In a watch case, the cover, transparent or not, opposite the dial.

Casing ring

A ring fitted around the movement to fill the gap between the movement and the case.

Disc

A flat, thin, round plate. The calendar disc rotates under the dial; its indications are shown through an aperture. Other discs display the day, month or moon phase.

Ebauche

An unfinished movement sold as such. Until circa 1850, an ébauche comprised only the plate, bridges, fusee and barrel. It was known as a blanc and was finished at the...

Finishing (Finissage)

The final operation in a process. On a watch case, the last stage in assembling the parts so that they function.

Green garnet

Demantoid garnets, a green, and very lustrous type of garnet. They have characteristic inclusions that look like horsetails. Demantoid garnets has a hardness of 6-7 and a specific gravity of 3.8 -...

Hour-wheel

The wheel that carries the hour hand.

Indicator

A watch's indicators are its dial and hands.

Jewels

The international term for the jewels (rubies) in a watch movement that are used as bearings for pivots to reduce friction. The movement of a quality watch has between 15 and 21 jewels.

Knot

A raised mineral inclusion in a diamond found at the surface.

Latitude

An angular distance that gives the location of a place north or south of the Earth's equator.

Moss agate

A green variety of agate. It is chalcedony that has dendritic green, red or black inclusions. The inclusions often form beautiful patterns and are used as watch dials or cases.

Nephrite

A family of the jade group of ornamental gemstones. Nephrite is slightly softer that jadeite and is often veined.

Ornamental gems

Any microcrystalline gemstone. Some examples are: Agate, Onyx, Sodalite, Malachite, etc. These ornamental stones are mostly used for watch dials.

Precious stone

A precious stone (also called a gemstone) is one that is rare, beautiful and durable.

Quartz oscillator

The regulating organ in a quartz clock or watch.

Regulating organ (regulator)

The regulating organs in a mechanical watch are the balance and spring whose function is to count time. A clock's regulating organ is its pendulum. In an electronic watch it can be a motor or a...

Tachymeter

An instrument for measuring speed.In watchmaking, a chronograph or sports counter with a scale for reading speed in kilometres per hour (kph) or another unit.

Under-dial work

Collective term for the mechanisms, such as for striking, a calendar or motionwork, between the dial and the dial plate.

Vane

Uses air friction to slow a moving part, for example the arm on a gravity escapement.

World time

Describes a watch that indicates, usually by means of subdials surrounding the main dial, local time (true solar time) in different world cities. Often these cities were chosen for their political...

Year

A four-digit indication of the current year that changes automatically at midnight on December 31st.

Zodiac

At the heart of countless legends and beliefs, since ancient times precious stones have had symbolic value. From the Jews to the Egyptians, each culture and religion has given a different meaning...