Choosing porphyry as a material was a bold and specific statement for late Imperial Rome. As if it were not enough that porphyry was explicitly for imperial use, the stone's rarity set the emperors apart from their subjects as their superiors. The comparative vividness of porphyry to other stones underscored that these figures were not regular citizens, but many levels above, even gods, and worthy of the respect they expected. Porphyry made the emperors unapproachable in terms of power and nature, belonging to another world, the world of the mighty gods, present for a short time on earth.