Definition

1. Noun:
   • Jewel (in a watch/clock mechanism): A small, hard, synthetic gemstone (traditionally ruby) used as a bearing at pivot points in the movement of a mechanical watch or clock to reduce friction and wear.
   • Jewel count: The term is also used to refer to the individual units in the count of jewels within a timepiece (e.g., 'mười bảy chân kính' means 'seventeen jewels').

Usage Examples

• Noun:
  • Đồng hồ cơ chất lượng cao thường có nhiều chân kính. (A high-quality mechanical watch usually has many jewels.)
  • Chiếc đồng hồ này có mười bảy chân kính. (This watch has seventeen jewels.)
  • Chân kính giúp đồng hồ chạy chính xác và bền hơn. (Jewels help the watch run more accurately and last longer.)

Advanced Usage

• "Đồng hồ [số] chân kính": A watch with [a specific number of] jewels.
  • Anh ấy sưu tầm đồng hồ mười bảy chân kính. (He collects seventeen-jewel watches.)

Variants and Related Words

• Kính (Ruby): While 'kính' can mean 'glass', in the historical context of watchmaking, 'chân kính' refers to synthetic rubies. The full term is more precise.
• Ngọc (Gem/Jewel): A more general term for gemstone, but not specifically used for watch bearings.
• Vòng bi chân kính (Jewel bearing): The technical term for the bearing assembly itself.

Synonyms

• Ruby (in watchmaking context): The traditional material used for jewels.
• Jewel bearing: The technical English equivalent.
• Pivot jewel: A specific type of jewel in the mechanism.

Notes on Meaning

• The term is almost exclusively used in the context of horology (the art and science of timekeeping devices). It does not refer to decorative jewels on a watch case or dial.
• A higher jewel count (e.g., 17, 21, 23) in a mechanical movement typically indicates higher quality and better durability, as jewels are placed at high-friction pivot points. However, beyond a certain functional number, additional jewels may have minimal practical benefit.

1. Jewel
   • đồng hồ mười bảy chân kính
     a seventeen-jewel watch