Jerusalem stone sealer/hardener

[aussie tiling]

I know its wrong choice but we are marrying to existing as they have extended entrance. The existing stone looks like it has a fine resin layer on top thats why lm asking as l think the owners will turn round and say why is it not finished like that

 

[Dumbo]

Maybe you could ask what the cleaners clean it with as they could be putting some sort of topical sealer on it .