This is a rare "zone dyed picture agate." Dye was selectively applied by a very skilled lapidary artist in specific areas to enhance the scene inside the stone.
Lucky me, I found this stone in the collection of one of my favorite stone guys in Colorado. I had beg and plead (and throw cash at his feet) to wrest it away from him. Luck you, I turned it into a pendant.
I didn't goof around with adding anything extra to this setting. The stone had to stand on its own, it's that unique and beautiful (of course, more beautiful in person).
The pendant is about 1 1/4 inches tall by a little under an inch wide. It is suspended on an 18 inch sterling silver snake chain.