R52 Oil and Wax Stain
This issue is unusual for black granite as it is very stain resistant. I have seen some dark stone absorb oils and grease over time causing it to appear darker. There are a few ways to attempt to resolve this issue, but without knowing the source of the stain I can only offer some general advice.
Since you tried cleaning area with acetone, it seems that the stain is deeper into the stone than just the surface. You could attempt to use a Poultice. This is a special stain removing formula that draws stains out through a chemical drying process. We distribute the HMK brand, R52-Oil and Wax Stain Remover Paste. You can see more information at
The only change I suggest to the instructions is to cover the paste (when applied to the stain) with a plastic wrap and allow the paste to dry slowly. As suggested, you need to neutralize the paste once finished with R55 Intensive Cleaner.
Another option is to try to flush the stain out through a steam process; take a wet terry cloth washcloth and lay it over the stain. Apply a steam iron (clothes iron) with the steam setting and if you have a steam burst function, use this to push steam into the stone. Sometimes this can dissolve and flush oils out of the stone.
If these methods don’t work you may want to consider using a color enhancing sealer: (only on the areas adjacent to the dark stained areas)
This may help blend in the darkness. You would still need to seal the areas near the sink with an invisible sealer like S34 Impregnator.
I hope this helps. Feel free to follow up with additional questions if needed.