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diamondtiling
No worries

Hi, i've done a fair few stone floors, and the sealer always seemed to be a bit of a problem, but the one i prefer to use now is the water based 'novacryl'
I always thin it and if you apply 3 or 4 coats you can get a really nice deep shine to it, almost like a wet look. but you do have to make sure you thin it for the best results.
I'm not sure what you would have to do to your tiles first to prepare them for this sealer tho, maybe someone else will have an answer to that. good luck anyway.
kev
That looks like Bastille limestone..
I think Aquamix Enrich and seal will sort that floor out colour wise.....remove the traces of old sealer and use the aqua mix one.