A precious stone, usually of substantial monetary value or prized for its beauty or shine.

Any precious or highly valued thing or person.

“She's an absolute gem.”

Anything of small size, or expressed within brief limits, which is regarded as a gem on account of its beauty or value, such as a small picture, a verse of poetry, or an epigram.

“a gem of wit”

To adorn with, or as if with, gems.