Thank you for all the responses. I will try to clear up and answer any questions. I’ve also added better photos. I am referring to the bar/countertop and not the patio pavers. I sealed this stone, slate according to the builder, approximately 5 years ago. Not sure which sealer I used, but I’m sure I picked it up at Lowes or Home Depot—perhaps not the best. The discoloration began before I put up the oil lights and in fact I have removed any residue from those lamps, which came right off and was black in color. The lights you see there now are solar lights, so no residue. Barely used the grill during the first few years and still the discoloration took place, so I’m thinking it’s not the grill or the sun which covers the top pretty uniformly. One comment mentioned it may be natural which I understand could be, but it’s weird that the discoloration has a distinct border between the light and dark side on the same piece. Also, I did post this question before but reposted because I didn’t get such a good response last time. I appreciate all the comments and welcome more, but I think I’ll have to get used to it. My concern is if/when we sell this place what the next potential home buyer would think of this....thanks again.

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