This fireplace may look simple, but let me assure you folks, it was anything but. When my clients moved in, the old fireplace was totally unusable, not up to code, and worst of all it was ugly. Not only was it covered in hideous "Spanish tiles", but it was about 3 times bigger in scale than it should have been. A classic example of bigger does not always mean better. I knew right away the entire thing had to go, the problem was finding a replacement gas fireplace unit that met our specifications on size, ventilation, and allowable distance from the television above for heat safety. No one wants their TV to melt.
We went round and round on the design, considering everything from fancy tiles to floor-to-ceiling stone, but ultimately we decided to keep it simple to match the architecture of the house. The floating ledge is made of the same Basalt stone we used on the countertops in the kitchen and it turned out beautifully, despite making my contractor want to strangle me. Apparently making a very heavy piece of stone float without visible brackets is tough or something.
Sources: Fireplace Unit: Mezzo Series from Heat n Glo // Ledge: Basaltina slab from Stone Source // TV: Sony 4K