Twelve-Angled Inca Stone
Peru’s Twelve-Angled Stone was once part of an Inca palace wall and is now part of a wall of the palace of the Archbishop of Cuzco. That entire wall, as well as the walls of Sacsayhuamán – a complex on Cuzco’s northern outskirts – are dramatic examples of ancient construction technology.
The walls feature heavy stones of varying sizes and shapes. The stones are made of igneous (volcanic) rock comprising various minerals that are mostly quite hard and difficult to cut – and yet they fit together so perfectly you cannot fit a razor blade between them.
How did the ancient Incas (or an even earlier civilization) manage this remarkable feat of construction? The walls apparently hold up very well under earthquakes too. As with many ancient wonders around the world, it is tempting to say ancient aliens had a hand in it.
“Oh no, not ancient aliens again,” you groan. After all, we are talking about just building walls – and, as the legendary entertainer Jimmy Durante might have said, you don’t need space age technology to Inca-Dinka-Do it. (Sorry about that.)
Every magic trick seems miraculous until you learn how it is done. In the case of the Twelve-Angled Stone and the Sacsayhuamán walls, one man may have figured out how it was done. That man is Helmut Tributsch, who grew up in a small village in the Italian Alps and describes himself as a “scientist and university teacher specializing in energy research.”
Tributsch and others have noticed that while the stones fit together perfectly in the front, and on the top and bottom, most are not as precisely joined in the back. Tributsch believes that although the huge stones were rough cut, dressed, and placed onto the walls – itself no small challenge – the work of creating the fine-fitting seams may have occurred post-placement through some sort of chemical process.
According to Tributsch, the Incas had access to highly acidic mud from their mines. When they applied this mud to the placed stones, it caused the stones’ silica surfaces to soften into a viscoelastic gel which filled the gaps. When the gel hardened, it produced extremely tight interfaces in the places where the mud had been applied. Tributsch further claims the process could be enhanced tenfold by adding oxalic acid containing plant sap.
All of that said, it remains a fact that subsequent attempts to replicate the incredible stonework found in the Inca walls have never quite matched the precision the Incas achieved.