À tact watch

Repeater watch (see complication) in which hammer and bell are replaced by a sharp pin which protrudes from the case to prick the finger once for each hour.A type of watch made after...

Bow lathe

The bow is a band of steel strung with a cord, generally gut, which drives the watchmaker's lathe.

calibre-cut

Small gemstones that are cut into special shape (usually a step cut) that are mostly used in watch bezels.

Dauphine

A type of hand in the form of an elongated triangle.

Escapement

A mechanism that is fitted between the gears and the regulating organ. Its function is to suspend the gears' motion at regular intervals and to supply energy to the balance. The main types...

Flinqué

Engraving done by hand using a graver or by machine using a rose-engine and comprising intersecting straight or wavy lines. The tool is always moved concentrically.

Grain

A unit of weight for fine pearls: one grain equals a quarter of a carat or 0.05 grams. In stone-setting, the grain is a shaving of metal lifted from the mount and bent over the stone to...

Hour-wheel

The wheel that carries the hour hand.

Indicator

A watch's indicators are its dial and hands.

Karrusel

A device similar to the tourbillon, the difference being that the cage is driven by the third wheel. Invented by Bonnicksen, a Danish watchmaker established in London.See complication.

Lever

A rigid part that rocks on a resting point. In watches, certain levers command a function or set a position.

Microsecond

A unit of time equal to one millionth of a second.

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...

Opale

An amorphous gemstone that shows the spectral colours called fire on either a white or black background. An orange variety called Fire Opal comes from Mexico and does not always have the fire of...

Pellaton (winding system)

The Pellaton automatic winding system was developed by Albert Pellaton, then technical director at IWC, and patented in 1946. The system was further improved in 1950.

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...

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...

Screw

A fastening comprising a cylindrical shaft, grooved along part or all its length, and a head with a slot for the screwdriver.

Tourmaline

A dichroic gemstone that comes in all colours of the rainbow. Some crystals are bi or tri coloured. Tourmaline has the greatest colour range of any gemstone. Tourmaline has a hardness of 7-7.5 and...

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...