What is the most valuable crown in the world?

Could you elaborate on the criteria used to determine the value of a crown, especially in the context of the most valuable crown in the world? Is it based solely on monetary worth, or does it take into account historical significance, cultural importance, and rarity? Additionally, are we considering only crowns that have been worn by royalty, or are there other types of crowns that could potentially hold greater value? It would be fascinating to learn about the specifics behind the crown in question, including its origins, materials used, and any notable events associated with it.