I had the exact same problem, red wax dripped from the mantle to the quarry
stone hearth and the facing stone. I believe it's a sandstone.
I tried everything to no avail. I got off all of the wax that I could. The
stone was stained. So I got a color chart from a Sherwin Williams store and
got a latex paint that was close to the color of the stone. The stones were
different shades so an exact match wasn't necessary. I painted the stone a
couple of times and you would never know that it had been painted. I think I
may have thinned the paint a little so it would soak in.
And I got a bonus. We have a heat-a-lator fire box. There are two intakes on
the bottom sides of the opening and two outlets on the top. It has a fan. It
draws the air in the bottom, heats it in the metal chamber and blows it out the
top. A couple years ago I converted to non-vented gas logs. I bought a sandy
substance at the paint store. This is for adding to paint to paint steps, ramps
etc. to provide traction. I mixed some with the "fireplace" paint and painted
the grilles for the heat-a-lator and the gas line which was on the hearth at
the back after coming in from the side of the house.
They all blended in beautifully!