If it were b/ween the two, I'd rule out marble & try granite instead. Particularly for a suspended wood floor. BUT, things are as Twl explained & all other have illustrated, i.e. which frequencies are you acting upon & what compromises are you ready to make (i.e. acting in one direction can bring along unwanted effects from a totally different direction).
Among others here, Jadem6 & Redkiwi have spent a LOT of time trying all available materials under the sun under their components :)! Maybe they can add an idea or two... Cheers
Among others here, Jadem6 & Redkiwi have spent a LOT of time trying all available materials under the sun under their components :)! Maybe they can add an idea or two... Cheers