It's a stink bug!
Whenever I see a bug that interests me, I photograph it, then look it up on the internet; same as one might look up an unfamiliar word in the dictionary. I do the same with plants, butterflies, etc. Lifetime Learning: keeps me out of taverns. So, this stink bug: looks like a shield-shaped chip of jade. Very pretty, did not stink and this is the only one I've seen here.