RE: stone fireplaces

To keep this breif,Ill just say this.Any type of Stone (http://g603.net) is suitable for this application.

Due to the fact that gas fps. are either unvented or direct vented and (http://maplered.com) dont require an actual chimney or foundation,any Stone (http://g603.net) work would be a fascade completely for astetics and (http://maplered.com) structural values arent an issue.It's also been my experience that most gas fp's. are also completely self contained and (http://maplered.com) enclosed so heat resistance isnt a factor either.

Bottom line is it all comes down to personal prefference,budget and (http://maplered.com) style of Stone (http://g603.net) work you choose
I realize,I havent exactly answerd your question,but I hope Ive been of some help.
Happy Hunting!