what are these gems called?

please excuse my ignorance, but as far back as I can remember Ive seen these jade green squares in old Chinese restaurants and many of the members home tiki bars, and have always wondered what are they called, are they hard to come by, are they glass,and are they expensive? thanks all !!

There is a lot of Jade Tile info here in this previous thread.

For general search purposes, call them 'Chinese openwork tile'. They were made in colors other than green, too, and seem to have originated during the Ming Dynasty.

Oceanic Arts has them $45.00@. Leroy will be the first to tell you that he wished theirs had sharper detail. Sounds like a lot of moolah but 4-6 pieces are usually enough for a home bar and they never wear out.
Cheers

awesome!!! thanks so much everyone for the help! now I know I can't afford them!! lol