The most scratch resistant and durable of all crystal types (mineral glass, acrylic, etc.) with a value of 9 on Mohs scale of hardness (diamonds are 10). A watch crystal, exhibition caseback or case itself in rare models can be made from this synthetic sapphire (crystallizing pure aluminum oxide at extremely high temperatures).
A rare form of Perpetual Calendar watches so advanced they account exceptional non-leap year years (the year 2100, 2200, etc). Only a handful of watches have ever been made with ultra-complex movements capable of this.
A watch featuring a rotor on the movement that spins either one or both ways as the wrist moves throughout the day, winding the mainspring without the need for manually rotating the crown. Also known as automatic.
A non-metallic material (originally used in semiconductors and microprocessors) that has recently been employed in movements as an alternative to metals (brass, steel, etc.), most commonly in the escapement. It’s lighter than metal, antimagnetic, completely corrosive and very wear resistant, and requires little or no lubricant.
When a watch is stripped down to reveal the workings of the movement, reducing or even eliminating the dial while plates and bridges on the movement are hollowed out to expose gears, the balance wheel, escapement, etc. Watch hands that are minimized without center portions (just outline borders) are also referred to as skeleton hands. Also known as open-worked.
A watch decoration usually seen on the dial (commonly on sub-dials) with a tight pattern of spirals.
A chronograph with an additional seconds hand (and pusher) that can time two events simultaneously that start together, but end at different times (a race, for example). When the timer is activated, both seconds hands move together superimposed, but one stops when a pusher is hit while the other continues. Also known as a rattrapante chronograph.
A watch that is highly legible, durable, shock and water resistant, and generally designed to withstand the rigors of sport (and separate from the dive watch category). Two of the highest regarded luxury sports watches are the Audemars Piguet Royal Oak and Patek Philippe Nautilus.
Small bars with retractable end pins (via an internal spring) used to attach a strap or bracelet to the case lugs.
An iron alloy designed for both corrosion resistance and strength, comprised of elements including chromium, nickel, carbon, silicon and manganese. It’s the most common metal used for watch cases and bracelets, with the 316L grade (superior hardness and corrosion resistance) most often utilized. Rolex uses the harder 904L grade steel in all its watches.
A precious (white) metal with a lustrous, highly reflective silver surface often used for luxury watch cases and bracelets. Sterling silver is 92.5 percent silver with the remaining metal principally copper to increase hardness. The metal easily tarnishes and watches often have a protective coating.
A leather, canvas, rubber or other non-metallic band attached to wristwatch lugs to secure the watch to a wrist (alternative to hardened bracelet).
A small, secondary dial within the main dial providing additional information beyond the central hands. This includes offset seconds, chronograph counters, date, hours and seconds in a regulator setup, and more.
A decorative dial pattern reminiscent of sunrays with almost imperceptible lines radiating from a central point. This is done with a brush containing metal filaments. This technique can also be referred to as sunburst brushing.
A seconds hand that glides continuously around the dial based on the mechanical movement’s frequency as opposed to one that jumps every second, typical of a quartz movement (or dead seconds).
Refers to a watch that meets strict standards and can be labeled as “Made in Switzerland.” Standards include the movement being manufactured and assembled in Switzerland, at least 60 percent of manufacturing costs being Swiss and the final inspection occurring in Switzerland. Swiss Made designations typically add some prestige to the watch.
