I would like to fix this small hole on marble countertop. It was caused by a sharp knife edge. Goal is to make it even and smooth again but not sure what i need to do. Any help/advice is greatly appreciated. Thanks in advance.
Epoxy is the way to go, but I would not dremel it out, leave it irregular as it is. It will need to be CLEAN, no contaminates, otherwise it may require a dremel tool. Keep it irregular since the "marbling" is irregular too, it will blend in better. Over fill slightly and use a very sharp single edged razor blade to cut the excess off. You can use a clear epoxy, that will pull color from the surrounding stone. I believe clear epoxy is still a little milky in color, so that will blend in even better.
Your home store usually carries epoxy repair kits. Note it is almost impossible to match colors I found a kit a few years back that used a putty like 2 part epoxy you mixed the putty until you got it close in color the trick was to not end up with a solid color funny that a solid white patch the exact color shows up like a neon sign but add a gray stripe and it looks better then sand and seal, the epoxy I used took up to 8 hours to fully cure even though it set in less than 10 minutes, so I waited until the next day buffed it out cleaned and resealed the entire side. I wish I had photos to share I got the epoxy kit at a home store called Jerry’s a competitor to Lowe’s and Home Depot in my area. I have used other kits that were more liquid and colors but if you can find the putty one I thought it was the best and it was there recommendation to not have a solid color patch, but the 2 part or actually 3 part if you count the colors made a patch I had trouble finding after sealing the customer was ecstatic.