The slate fireplace in my home is about 95 years old. It is in great condition but looks a bit tired. I sometimes oil the slate to spruce it up a bit, but would really like to polyurethane it to cut down on maintenance yet keep the front shiny to highlight the colorations of the slate. 1.) Can I poly this slate to cut down on maintenance? 2) If yes, would I use regular polyurethane?

Thanks!

hom2vt