Kieran
These customers never cease to amaze me. They go out and purchase a dull slate then want it highly polished. It's a bit like me going out and buying a red car then telling my local garage to make it yellow.
Anyway "Rant Over" either use LTP Antique Wax and buff it or use a topical sealer such Aqua Mix Seal & Finish Low Sheen 2-3 coats then Aqua Mix Floor Shine & Hardener 1-2 Coats.
Kev Martin
Marble Life Ltd