Step 1: Identify the characteristic material of Mauryan art.
A defining feature of Ashokan pillars and their capitals is the material they were carved from. They were monoliths, carved from a single block of stone.
Step 2: Specify the type of stone.
The stone used was a fine-grained sandstone, quarried from Chunar near Varanasi. This particular sandstone was chosen for its ability to take a very high, mirror-like polish, known as the "Mauryan polish," which is a distinctive characteristic of these sculptures.