Created by stone or copper tools? These false doors defies anything we knew about the technological capabilities, carved from the notoriously hard andesite stone. Cutting and shaping andesite rock with such accuracy is a task that would be difficult even with modern technology.

The stone is resistant to fracturing and does not yield easily to tools made from softer materials. The traditional methods of the Inca civilization involved stone or copper tools, which would likely result in rough, uneven surfaces and would struggle to achieve the sharp, clean lines seen in the false door.

The sheer precision of the angles, the smoothness of the surface, and the lack of tool marks suggest that an alternative and far superior method was used to achieve this. Surface of the stone, upon microscopic inspection to see if there were any marks from chiseling, revealed layers of melted andesite instead of chisel marks which had transformed into a glassy, obsidian-like surface. This discovery led them to question the kind of heat necessary to achieve such a transformation.

To melt andesite, which is a volcanic rock primarily composed of plagioclase feldspar and pyroxene, into obsidian, extremely high temperatures are required. Andesite typically melts at temperatures around 1,000°C or 2,000°F. However, to transform it into an obsidian-like material, the heat would need to be even more intense, likely reaching temperatures in excess of 1,200°C or 2,200°F. This kind of heat is far beyond what ancient or even early modern humans could produce with traditional methods such as wood or coal fires. This observation suggests that the surface of the andesite was subjected to some kind of unknown, intense heat source.