As above, and if feeling brave, tape off the straightest possible line of the narrowest exposed cut side............and paint it matte black. Same paint as you'd use to paint the inside of a firebox. All three sides, and just the half inch to inch , which will reduce the look of the exposed edge and read simply as a bit more frame... After that? Stop staring at it.

A consideration of the cladding prior to setting the firebox, would have been more ideal. Calling a stone mason and paying for a knockdown of the very bulky offenders isn't a bad idea either : )

Knocking corners off manmade lick and stick stone is going to expose the concrete. You can already see the aggregate on the cut ends, which looks awful but at least it's a clean cut. If you're trying to keep with the modern look you could have a metal fabricator make a U-shaped "frame" of black painted 1" square stock to butt up against the cut edges and hide them.

Should have mitered the edges. Or bought the corner pieces. Make either one of those happen and learn your lesson.

You've done a great job! Move on - it won't be noticeable in a few months.

Draw a perimeter line, cut the stone back, and install perimeter stone casing.

Its lookin' great so far!

following

Joseph Corlett, LLC has a really good idea and could look even better than corner stones with less work...

Never got around to posting the finished product. Turned out better than I could have hoped for!!!

How did you end up finishing the edges? Can’t tell from pic. Looks great!