What is the prefix for jeweled?

There isn't a specific prefix that means "jeweled". However, you could use some prefixes that convey a similar meaning:

General:

* Gem-: As in "gemstone" or "gem-studded"

* Jewel-: As in "jewel-toned" or "jewel-like"

More specific:

* Dia-: For diamond-like things, like "dia-studded"

* Chryso-: For gold-like things, like "chryso-colored"

* Rubi-: For ruby-like things, like "rubi-red"

Ultimately, the best prefix will depend on the specific context and the desired meaning.