You need to make sure you observe the recommended clearances around the firebox, the amount of space above and on either side of the firebox that must be composed of fireproof material like brick, slate, marble or stone, or some other noncombustible material. If your fireplace is a prefab, the manufacturer's owner's manual should give you the clearances. If your fireplace was custom built, you could ask a chimney sweep for his recommendations about safe clearances. If it was properly designed and built, it already has noncombustible material around the firebox. So your only concern is not to disturb that, or to replace it or cover it with another noncombustible material for decorative purposes. Just make sure your bookcases are outside the clearances. By the way, if you haven't cleaned your chimney, you should do it soon, while chemney sweeps are idle. If you don't know one, ask around for recommendations from friends or neighbors. Good luck with your plans.

Thanks for your comments, cloud swift and lavender lass. I appreciate it. I think I may not have clarified my question as well as I could have so I'm going to try again and I beg your patience as I try to explain what I'm struggling with. Anyone else with an opinion, PLEASE jump in. In the design I've created (based on the inspiration pic) there should be 5" of tile and 7" of wood surrounding the firebox. The tile designer felt that if we install the stacked travertine mosaic tile we should have 9" of tile around the firebox to really show off the effect of the running bond stacked tile. I think that will result in the surround being too wide, too tall, and will end up being too massive for the room. It also makes the tv way too high on the wall. DH really likes the look of the stacked mosaic tile and would like to use it. So my question is if I only have 5" of tile showing on each side of the firebox will it look okay to use a 1"x2" stacked stone? That's what I'm struggling with. I'm afraid it will look silly to have only 2-1/2 stones showing between the firebox and the wood. I think we should either go to a 1" mosaic tile or go find a remnant of marble. The island countertop is Cafe Creme granite, which I think will be too busy for the inspiration look, and the perimeter counters are Hanstone Tiffany Grey quartz, which I think will be too dark. I found a better picture of the fireplace that doesn't show the optional trim around it (thanks for asking about that wide trim Lavender - it made me really get into the manual and their website and dig for the answer about the size of the trim.) and I put together a quick sketch showing the 1x2 inch tile on one side of the fireplace and a 1x1 inch tile on the other side. I left off the slab option because that is what is showing in our inspiration pic above. What is your vote?

Erinct, I wasn't trying to lay down the rules of OT etiquette. To me the topic was in a grey area and I argued with myself a bit on whether to mark it OT or not. Sorry to hear about the poison ivy - that can be hard on the sufferer and his family. I hope he is feeling much better now. For textural and informal, someone had a fireplace with long thin stone kind of stacked on edge. To me, the pictures that you posted look pretty formal because of the style of the wood columns, mantle and, on the top one wall detail above the mantle. Here's our fireplace waiting for the surround Here is a close-up of the fireplace with a sample of the stone for the surround, cherry door (right material, but in the kitchen door style), and a piece of the maple flooring. We don't have a sample of the black stone that will be the hearth extension on the floor. Our surround will be pretty simple; just the stone covering the drywall under the mantle and a simple thick cherry mantle. The family room cabinet doors will be in this style, but natural cherry:

Porcelanosa has thin porcelain slabs in sizes you need. Used on my fireplaces. The problem might be finding good fabricator https://www.porcelanosa-usa.com/products/tile.html/porcelain-panels/liemdark-nature