21 jewels意思
"21 jewels" is a term often used in the context of mechanical watches to indicate the number of jewels used as bearings for the watch's moving parts. In a mechanical watch, jewels are used as bearings for the pivots of the balance staff, the pallet fork, and the escape wheel, among other parts. These jewels reduce friction and wear, which helps the watch keep time more accurately and reliably over time.
The term "jewels" typically refers to synthetic rubies or sapphires, as they are the most durable and least reactive materials for this purpose. The number of jewels in a watch can vary widely depending on the design and complexity of the movement. A higher number of jewels generally indicates a more complex movement with additional functions, but it is not always a direct measure of quality.
A watch with "21 jewels" would have 21 such bearings, which is a relatively common number for mid-range mechanical watches. It suggests a level of precision and craftsmanship, but the number of jewels is not the sole determinant of a watch's quality or value. Other factors, such as the materials used, the accuracy of the timekeeping, the pedigree of the watchmaker, and the overall design and finish of the watch, also contribute significantly to its worth.