Then spend big bucks on a piece of marble cut to size or some other materil one piece . I wouls alos like to see this from further back it looks like a high hearth too so that will also need to be changed and with no clue as to your style not many other ideas

More wanting help on what materials I can use other than grout/tile. We don’t use the fireplace but don’t want to rule out the option.

Granite may be an option. I have (absolute?) matte black granite slabs as the surround and hearth for two fireplaces (one is cherry and the other is BM Linen White). It looks great. But it’s hard to say whether black will work for your room.

Go to a stone yard and look at remnants for the surround. You will have to have it cut to four pieces, two for the sides, one for across the top and one for the hearth. Hopefully those fire doors will come off and you can spraypaint over the brass. Maybe it's not the height of fashion, but IMO that is pretty neutral tile and it looks like a nice mantel, so if it were me, I would just paint out the brass and be done with it. But without being able to see the whole room I'm not sure how it fits with everything you have.

The mantle probably should be and may have to be removed in order to change the hearth. Likely that it can be reinstalled. But you may decide to really change things up at that point. IOW's, don't box yourself in thinking that you need to work with the existing mantle.

Paint the tile

Replace the tile with tile

Replace the tile with granite

Thank you!

My daughter used a special fireplace spray paint to get rid of the gold! It was perfect.

I painted out the brass twenty years ago. It still looks great.

Ageee with going to a stone yard and purchasing a remnant, it can be really economical