Like other metamorphic rocks, marble has no fossils, and any layering that appears in it probably does not correspond to the original bedding of the precursor limestone. And like limestone, marble tends to dissolve in acidic fluids. It is quite durable in dry climates, as in the Mediterranean countries where ancient marble structures survive.
Commercial stone dealers use different rules than geologists to distinguish limestone from marble.
For more photos see the Metamorphic Rocks Gallery.