I’ve never seen marble that color of blue. Does anyone know where that came from?
Tough to say, the Romans got around, and if they liked something, they weren’t too worried about cost.
Actually, it could be lapis lazuli, that has been mined in Afghanistan for 7000 years now, and been of interest quite far from Afghanistan for nearly that long. The purple stone *could* be true porphyry, which was mined in Mons Porphyrtes in Egypt. If either of these IDs are true, this is not just another high-status Roman dwelling.