Anti-magnetic

Describes a watch that is protected against magnetic fields.

Bar

Unit of measure to indicate a watch's water-resistance, specifically its capacity to resist pressure, based on standard atmospheric pressure defined as 101.325 kilopascals (kPa) equivalent to...

Clock

Any device (water clock, candle clock, sundial, sandglass, mechanical clock, etc.) whose function is to indicate the time. Today, it refers exclusively to a non-portable mechanism intended to work...

Dart (Guard pin)

In a lever escapement, a small metal pin which prevents accidental movement of the fork.

Engine-turning (Guilloché)

A style of hand or machine engraving with intersecting wavy or straight lines. When the piece is moved horizontally or vertically against the tool, the finished effect is guilloché, compared with...

Full cut

A brilliant cut diamond.

Gregorian calendar

The calendar now referred to by the majority of countries, introduced in 1582 by Pope Gregory XIII in his reform of the Julian calendar. With its 365.25 days, the Julian year was 11 minutes...

Hardness

The resistance of a material to scratching and wear. Hardness is measured using the Moh's Scale. This scale indicates that one substance can scratch the substance below it and scratch itself. For...

Integrated circuit

A group of electronic components and their connections, performing one or more functions. Integrated circuits for watches measure just a few square millimetres.

Jewels

International term for the rubies in a watch movement.

Knot

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

Lapidary

A craftsman who cuts, polishes and sells coloured and precious stones. A lapidary who specializes in diamonds is called a diamond-cutter.

Niello

An enamel-like alloy of lead, copper, silver, sulphur and sal ammoniac (ammonium chloride). Niello paste is applied over incised gold or silver then fired in the enamellist's furnace. Excess...

Oscillator

A device such as a pendulum or balance that produces the oscillations that divide time into equal units: a balance spring in a mechanical watch; a quartz in a quartz watch.

Pinion

A watch part, generally with 6 to 14 leaves (teeth). The different parts of the pinion are the leaves, the seat to which the wheel is riveted, the shank and the pivots.

Quartz

Silicon dioxide. Also called rock crystal. Quartz has the specific property of vibrating at a very high frequency (32 MHz) placed under electric current. Under certain conditions, it...

Rim

A circular mass held by spokes to form the balance.

Second

The basic unit of time corresponding to 1/86,400 of the mean solar day, which is the period of rotation about its own axis of an ideal Earth describing a circle round the Sun in one year, at a...

Turning arbor

Slightly tapered arbor in tempered steel for turning the hour wheel.

Universal (watch with universal hours)

A watch whose dial shows the time of places in different time zones.

Vermeil

Silver covered with a thin layer of gold.

Water

The transparency and clarity of a precious stone; the orient and lustre of a pearl.

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...