Alabaster? Bust

Just got back from my trip and found this beauty today. Stopped at a thrift store on the way home and got this. The lady in the store thought this might be marble, but I'm guessing maybe alabaster or something else. This bust lifts off the base and because of a dowel can be turned around on base. This piece is massive and weighs almost 40 pounds!! She looks Roman or Greek with the toga style dress. I have not seen any names or marks on this. There are a couple chips on base and a few on the bust, but still a nice statement piece.