I have multiple stains that I believe to be grease based from my slate heart. I tried a wet cloth with some dishwasher soap but it didn’t make any difference. I’m afraid to try anything stronger. I’ve read a mix of hydrogen peroxide and banking soda paste but don’t have the stones to try. Any idea ?

 

You would need to use stronger solvents. Goof off, acetone, something like that.

 

Would Simply Green or degreaser be ok? I am always hesitant to clean stone given how different chemicals can be an issue.

 

It is grease/oil not a boo boo so hydrogen peroxide won't help. Think of things that work with grease except I would bypass soaps and cleaners and go right for solvents like XSleeper mentioned. Test a small, not visible spot on you stone to see if the solvent will leave any marks. Some stones are oiled or sealed which will will affect how you proceed.

The oil has probably soaked into the pores of the stone so it's not a matter of cleaning the surface. You need a solvent that can soak into the stone and dissolve the oil so you can blot it off with a rag. You'll have to repeat many times and hopefully each cleaning cycle will remove a tiny bit more of the oil.

If your stone is sealed or the solvent is leaving a mark I'd consider a different tack. Consider oiling the entire hearth to match the stained spots. The oil will further protect the stone for stains in the future.

 

OK. I'll try goo gone or acetone and let it sit for a bit and then wash with clean water as it hopefully dissolves?

 

As he said you need to blot it with something. Cotton ball or cotton rag or something. You don't just put it on and let it dry.

 

Goo Gone is oil/oily based. I wouldn't use that.

Things that I would try in order of strength...... white vinegar, lighter fluid, acetone and finally muriatic acid.
Must use blotting.

 

Avoid acids, including muriatic/hydrochloric, without testing first. Slate is a sedimentary stone that usually contains a lot of stuff, some of which can be dissolved/attacked by acids. Acid etching is something you can't clean off

 

Wouldn't white vinegar etch it?

 

The idea is to try a small amount first. Try to find something that will dissolve the stain.

 

Yes, white vinegar is an acid so it could etch the stone. You need to test it on an area you can't see before using it on the highly visible top. Plus, vinegar isn't great at cutting oils and grease. It's touted a lot online as a "natural" cleaner but it's nowhere near as good as grease cutting soaps, cleaners and most solvents.

 

I actually found an easier method. I turned the fireplace on high and the surface got so hot that the substance lifted to the top and I was able to use a dry cloth to remove nearly all of it. I think a few more times and it will be unnoticeable.

 

From the Natural Stone Institute:

OIL-BASED STAINS
Poultice with baking soda and water OR one of the powdered poultice materials and mineral spirits.

Applying the Poultice

Prepare the poultice. If using powder, mix the cleaning agent or chemical to a thick paste the consistency of peanut butter. If using paper, soak in the chemical and let drain. Don't let the liquid drip.

Wet the stained area with distilled water.

Apply the poultice to the stained area about1/4 to 1/2 inch thick and extend the poultice beyond the stained area by about one inch. Use a wood or plastic scraper to spread the poultice evenly.

Cover the poultice with plastic and tape the edges to seal it.

Allow the poultice to dry thoroughly, usually about 24 to 48 hours. The drying process is what pulls the stain out of the stone and into the poultice material. After about 24 hours, remove the plastic and allow the poultice to dry.

Remove the poultice from the stain. Rinse with distilled water and buff dry with a soft cloth. Use the wood or plastic scraper if necessary.

Repeat the poultice application if the stain is not removed. It may take up to five applications for difficult stains.

If the surface is etched by the chemical, apply polishing powder and buff with burlap or felt buffing pad to restore the surface.