Gas inserts require fuel and power routed into the existing firebox, you mentioned there is no gas, does that mean no gas available or just no gas service installed into your home? Also required is an intake and an exhaust, mine has 2, 4" inch metal flex pipes routed to the roof and attatched to a storm gaurd, your installer will take care of all of this, depending on your fireplace it is relatively easy (except for the no gas part). We had one installed and it remains to be seen if it was a good investment but after a single day, so far I really like it. I live in WI so once it gets really cold then I will decide:)

You will need to bring home a full sample set of grout like a presealed Laticrete in order to best decide. Hold up the sample slivers in the space to find the grey/pink/beige tone that best blends with that tile.

@HU-187528210 @Sammy @cat_ky @Kristin After reviewing the comments (thank you!) I hear what you are saying about not painting the tile. The different shapes would not look right if they were painted. *sigh* My issue is the tile around the fireplace doesn't match any other tile in its vicinity. (I know . . . pictures needed). There is a patio door nearby (to the right) of the fireplace that has a 2' x 6' tile floor area in white, using 2 different tile sizes. I feel like whatever tile was leftover from some other job ended up in this room. There is a hallway left of the fireplace that has a beige mottled floor tile, layed on the diagonal. That hallway goes to the kitchen. I am not changing the hall or kitchen floor, so changing the fireplace look *somehow* was my next thought. The carpet in the fireplace room is only 5 years old, so re-doing the little patches of floor tile seemed out of the question. THAT, my fellow houzzers, is how I came up with the not-so-great idea of painting the tile around the fireplace insert. Honestly, I will table this issue, as I can see the best plan is to 1) leave it alone, or 2) re-tile. There are many fireplace inspiration photos on Houzz I can use for that. I appreciate everybody's input on this; it helped me think through the process.

We had the same dilemma. Ventless gas fireplace, found several tiles we loved but them could not find a hearthstone that coordinated that we liked. So we ended up getting what the granite fabricator said was 'super white' granite...but it doesn't look like any other stone labelled 'super white'. Looks like a light 'shadow storm'. Turned out very nice. One thing to check - our builder screwed up - the specs of the fireplace will state whether the hearthstone is needed. Builder told us ours did not. Builder did not read the installation instructions.....Turns out, it did indeed need one unless the fireplace is 6" above the floor.. ours sits right on the floor. BUT, by the time we figured this out, the hardwoods had already been refinished, and we didn't want to cut an opening and just plop the hearthstone in, even trimming it out, hardwood guy said it would look like an afterthought. Instead, our hearthstone sits on top of the hardwood. It's only an inch high, and luckily not in the way. Just not flush as we desired.