Step 1: Determine the key material in Mauryan art.Ashokan pillars and their capitals are identified by the material used: monoliths, crafted from a single stone block.
Step 2: Name the stone type.The stone was fine-grained sandstone, sourced from Chunar near Varanasi. This sandstone was selected for its capacity to achieve a high, mirror-like polish (the "Mauryan polish"), a unique trait of these sculptures.