post in design dilemma if not already.
I'm hung up on the fact that you didn't ask before putting the stone on - you could have highlighted the fireplace with a different stone.
A mantle is now the way to go. Maybe some recessed lights in the area

A large piece of art or sculpture would also accent it with focused lighting.

Eliminate whatever is tied to the fire screen.

Hi, I agree with yesterday's comment about adding a mantle. I suggest maybe some iron work art hanging above the mantle- see this picture: http://houzz.com/photos/374179

You have a beautiful stone structure around fireplace. You definitely want to highlight it. Get dark fireplace mantel (preferably wooden as it would blend in with other furniture you already have). It can be both floating above or framing fireplace. That way you will be able to place some frames and plants there. Over it you want to place either huge mirror which will expand he room or picture, definitely place wall light fixtures from both sides of any of your choice. Finally, get lots of big candles, candle holders (but light colors, almost white) and place them on the tile in front of fire place (you can also get a tray for organization). Room won't be overloaded, but fireplace area will stand out!