gem

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

(figuratively) Any precious or highly valued thing or person.

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.

(obsolete) A gemma or leaf-bud.

A type of geometrid moth, Orthonama obstipata.

(computing) A package containing programs or libraries for the Ruby programming language.

(uncountable, printing, uncommon, obsolete) A size of type between brilliant (4-point) and diamond (4½-point), running 222 lines to the foot.