Movements and Crystals

The movement of any particular watch is the heart and soul of the timepiece. Movement types include quartz, mechanical hand wind, and automatic (self winding).

Quartz movements are among the most accurate and reliable timekeeping mechanisms available. Over the years, watchmakers have developed quartz movements with the goal of supreme accuracy. These movements are powered by battery and are easy to service. Batteries typically last 2 to 4 years and are very inexpensive to replace. Quartz movements can be found in watches ranging from low-end department store watches to high-end Swiss luxury timepieces.

Mechanical Hand Wind watch movements are powered by the manual winding of the crown. Many watches featuring this type of movement have a power reserve ranging from 24 hours to 7 or 8 days. Some watch owners favor hand wind movements because they like the interaction with the watch and enjoy the historical feel of a mechanical timepiece.

Automatic mechanical movements are very popular among watch collectors and can be found in some of the most prestigious watches in the world. These movements are automatically wound by a pivoting weight that winds the mainspring barrel as the watch is moved around during normal wear. Power reserves are typically 24 to 48 hours.

The crystal on a watch is the transparent cover that provides protection for the watch face. Most watches are constructed with one of three materials used for the crystal. These materials are plexiglass, mineral glass, and synthetic sapphire. Each material has distinct advantages and disadvantages.

Plexiglass watch crystals are the least expensive to manufacture. Of the three primary crystal materials, plexiglass is the least likely to shatter but is also the easiest to scratch. Plexiglass crystals are most commonly found on low cost watches.

Mineral glass watch crystals are generally made from glass that is similar to what is found in windows. Frequently, mineral glass used in watchmaking is hardened to improve scratch resistance. This crystal material is a great compromise between cost and durability. A mineral crystal is less likely to shatter but does not provide the same scratch resistance of synthetic sapphire. Mineral glass crystals are generally found on mid-market watches.

Sapphire, both synthetic and natural, is one of the hardest substances on the planet. Sapphire is rated 9 out of 10 on the Mohs scale (diamond is rated 10 on the Mohs scale). The only notable downside to sapphire, outside of cost, is the brittle nature of the material. Due to the high degree of hardness, sapphire watch crystals are more likely to shatter than those made of another material. Synthetic sapphire watch crystals are most common with high-end watches.