A magical Transformative Weapon can turn into different weapons. Could this enhancement be used to get a quarterstaff made of adamantine, or a scimitar made of wyroot? (Assuming it was already made of these special materials before it was enchanted?)
RAW, yes.
I don't see why quarterstaves can't be made of special materials like adamantine anyway, considering in The Ruby Phoenix Tournament one of the end bosses specifically has a quarterstaff made from adamantine.