Definitions by Erik Mas

spinning a gem 

to pitch one hell of a baseball game. as close to, if not, a no hitter. To spin a gem is to pitch a very good game.

bob: hows lester doing?
pete: oh he's spinning a gem right now. its bottom of the 7th and he's got a two hitter shut out going.

spinning a gem by Erik Mas June 16, 2014