Mortar? Grout?

I'd start with a sanded mortar smear.

Not a fan of white washing river rock.

Maybe replace the river rock with something simpler.

That's tricky. Not sure what will stay in there. I would re think the white washing. Few people seem to be successful with that on that sort of rock. There are loads of pictures online - personally I think they look bad. Maybe something other than white?

Too bad you don't like the fossils.

The first ‘fossil’ is pretty convincing but the rest are clearly fake. You need something that will stick and can be modeled to have stone texture easily. My first thought was the powdered drywall mud/ plaster of Paris. I think though I would use epoxy modeling paste- you cut off a chunk, mix it in your hands, and mush it in place. Press something into the surface while it’s setting to match the stone texture.

My biggest fear is if I fill them in that the texture won’t be the same as the rest of the rock. Here is the final - and worst - imprint.

I would love to redo it, but first quote I got was $10k as it would be a pain to remove the whole thing.

Totally natural looking… what were they thinking?

https://www.gardenweb.com/discussions/5827091/how-to-paint-river-rock-for-an-updated-look

Still thinking about a fix four years later?

These are engraved modern versions of Native American art. They are not supposed to look like fossils. You can try filling the engraved indentations with Bondo and then handpainting them with stippled paint to match the rock surface. Practice on a small version first to see if it works out (you can order a fridge-magnet size engraved rock for under $20).

Might be better to drywall over the rocks. If you post a picture of the whole thing you will get better help. Is it a wood burning fireplace?

I ahte the look of painted rock and I would like to see some clue as to the decor going in this space and the FP in the space .

You could get some more bids to remove the rock and replace it with something more to your taste as that number sounds high. In a previous house we removed a 17x8 ft stone fireplace surround with a full length hearth in an afternoon. Then if you found a tile you liked it shouldn't be very expensive to redo the wall.

If you are d.i.y. and crafty will suggest filler of some type and then painting that to match the rocks. Actually I think they have a certain amount of kitschy charm.

Take a pic from far away so we can see the whole thing.

Careful what you paint.

These are not fake fossils. They are made to look like primitive carvings. Personally I find them benign and would just leave them.

Here is the whole fireplace.

It’s really not that bad. Paint the mantle the same color as your trim and replace the screen or paint it black with high heat spray paint. Once you accessorize the hearth and mantle, you’ll hardly notice the faux fossils.

I think it gives your room some warmth and interest. There are a lot of gray rocks that go well with your gray colour scheme. Maybe a bit of gray wash over the reddest stones if you don't like their colour? Looks like it would be fairly straightforward to cover the upper part with drywall. Or the lower part too if it isn't wood burning, as long as it's to code.

I think the carved stones are interesting. They're not meant to be fossils, just rock carvings aka petroglyphs.

Leave it as is. I could only find one of the inset figures, they don’t stand out. If you really hate them, get some craft paint and paint them the same color as the stone. It’s a nice fireplace, don’t make it look like a pile of marshmallows.

It looks great the way it is. Goes well with your paint. Just ignore the carvings. I think whitewashing that fireplace would make it look bad. Now, it looks natural. Once you white wash it, it will keep the texture, but have an unnatural look. If you do go ahead and whitewash it, be sure to do with with a paint that can be washed off, so the next owners of your house aren't stuck with the whitewash.

Wow, I had never seen the pile of marshmallows look before and now I don’t know if I can unsee it!

If you really hate it, I would get more bids on building a drywall box over the upper portion. White paint is not going to give you the clean modern look that you are going for. Natural materials like stone and brick are certainly part of the modern palette, especially MCM.

You can research the meaning of your fireplace Native symbols: The whole set may be a lovely message. I would not paint that fireplace, whitewash or otherwise.

I'd chisel off the top half over the mantel as someone below suggested and hire a drywaller to clean up my mess. That should cut your $10k estimate down a bit. You can also try sponge-painting with concrete dye over some of the rocks to get it in the color range that you like. Getting the inside of the symbols to be the same color as the rock in which they are carved can also help make them look less noticable.

I tiled over a brick fireplace and as am very very happy that I did.

I think Beverly’s examples of painted rock fireplaces is all the proof you need to NOT do anything with those rocks. Getting rid of the bright brass and orange-y mantle should be the focus.

It's too bad you don't like it - compared to some of the stone fireplaces we have seen on here, yours is quite nice.

It is your home and you dislike it so I think the suggestions of covering it are the best options. Reference Beverly's pics above for how bad that river rock will look painted.

Have someone look at it and give you a bid to cover it with drywall or cement board and then you can tile it. I am sure that will be less expensive and less destructive.

Good luck!

I don’t think they’re worth the cost of replacing. I would look into replacing the mantel and screen.. That would be cost effective and give you a new look.

I think your fireplace is quite nice. I would leave it alone.

I am also thinking this FP is not bad and those little items are a bit of a conversation thing so I agree leave it alone . If it really trully makes you crarzy why not check into building a frame out from the wall and doing tile a lot less than ripping out the rock I bet . Is that a gas or wood burning FP ?

I’d be tempted to remove the mantle and find a large piece of art I liked - that would cover a lot of them, then a simple basket with some birch logs in them on one side could also help

Not a fan of the 'fossils' but anything you do will only make it UGLIER. It's really a rather neutral stone as these things go. Ignore the 'red tones' and move on.

Looks better in black! Great job.