Collocations for gem - noun

precious, priceless

dripping with gems
a millionairess dripping with gems and pearls

encrusted/studded with gems
a belt studded with priceless gems

little | absolute, real
The second side of their new album contains some real gems.

hidden
She worked in the antiques trade, searching out hidden gems in the most unlikely places.

architectural
architectural gems like York Minster

a gem of a sth
This is a little gem of a flower.