Step #1: Gather Your Supplies
The most common solution for a crack, scratch, or chip is to fill it with epoxy adhesive. Epoxy is a thermoplastic adhesive material. You should be able to find this from your local hardware store or online. You may even find a countertop repair kit which would have natural stone pigments and come in the form of a paste for you to mold and shape to fill any gaps in your countertop surface. If you have a light colored countertop, you can even use superglue for your chip repair.
This step is optional, but you can use a diamond tipped drill bit (cost $15-20) to grind a bit of dust from an area of your countertop that isn’t visible, such as underneath, and mix that into the adhesive to help match your stone.