That should have been “big” not “bid”. Stone appears to be an agate- very colorful and beautiful with lots of semi transparent areas.
Maybe cast, but looks like nice well done heavy stamping. That stone looks like a piece of Arizona rainbow petriried wood. Real nice bracelet.
I thought this stone was petrified wood too. I know we are “Turquoise People” 
but it would be great to get a crash course in how to tell petrified wood from agate since sometimes it’s hard to tell which is which.
Even on a fossil forum it is a question that isn’t answered easily Petrified wood or agates? - Fossil ID - The Fossil Forum
Now that’s funny! Thanks Jason. Seems like even at a cellular/microscopic level there still may not be conclusive science that all agree on. You say to-may-to, I say to-mah-to. Whatever. I’ll read through both pages with a glass of wine! 