Put few more info, color, size and use for what..

Depends on the shape, location, type of stone, how you plan to hang it, and what else is going on in the room. Can you post pics?

First of all, I don't think that furniture is comfortable enough to sit and watch TV, so the TV should be remove from that room, the purple wall paper and the purple furniture is too much, you should consider another color for that wall and the furniture against the wall it doesn't look good. What is that room at the end is kind of dark and I cannot appreciate exactly what is the purpose of that room. I'm a firm believer in skylights, we have skylights in the laundry room, kitchen, living room and office, they make a big difference. (if you cannot have skylights (or tube lights) can lights are a great option. There are a lot of great ideas from everyone. I can't wait to see the after photos.

Well I'll try to make a 3d of the room and upload it. But that will take some time. Thank you :)