* Pre-: This prefix means "before" or "prior to". While not directly related to "precious", you could use it to create words like "pre-loved" (referring to something that was previously owned) or "pre-treasured" (suggesting something that was valued before).
* Pro-: This prefix means "in favor of" or "for". Again, not directly related, but you could use it to create words like "pro-precious" to emphasize the importance of something.
* Super-: This prefix means "above" or "beyond". It could be used to create a word like "super-precious" to emphasize the extreme value or importance of something.
Ultimately, the best prefix to use would depend on the specific context and the intended meaning you want to convey.