
The fact that the lemon juice did not interact with your stone is great news. It means that your stone only needs to be sealed good.
How old is your installation? If it is a pretty recent job, I would suggest you contact the stone company and have them come out to properly clean and seal your stone. It sounds like the area where you are cooking might have some oil spots, but those can be taken care of pretty easily. Be sure to have the guys clean those completely before sealing your tops, though.
Good luck!
]]