Carved Inner Corner Replication

Stella Nair recreated the sharply carved 90-degree inner corners found at Puma Punku (Tiwankau) using only stone tools. She used an obsidian blade as an incisor along the inner edge, replicating a similar cut line as seen on the site's stones. From the book The Stones of Tiahuanaco by Jean-Pierre Protzen and Stella Nair.