the crown jewelsthe crown, sword, jewels worn by a king or queen for official ceremonies
[TahlilGaran] Dictionary of Contemporary English ▲
crown jewels n. pl. The crown, staff, and jewels used for the crowning of a king or queen; the crown and jewels representing royal power and authority.
The crown jewels are handed down from one king to the next when the new king is crowned. [TahlilGaran] English Idioms Dictionary ▲