Evidence of Vitrified Stonework in the Inca Vestiges of Peru (cont.)
By Jan Peter de Jong & Christopher Jordan

RESULTS

Microscope Photos

Photo 1: The Vitrified Surface of the Stone

The sample as photographed by the microscope. It shows two distinct regions, the surface layer and the body stone. There is a less distinct intermediate area between the two that seems to transition from stone body to surface layer. Samples from all three regions were subjected to detailed analysis.

(The line at bottom is 21 micrometer)

Spectral analysis

Composition of the Surface Layer

Note: The full set of photos, spectra and tables can be found in the full article

The main body of the stone shows the spectral composition for limestone. High levels of calcium, carbon, oxygen and minor trace elements are the constituents of limestone. This is not unusual since the University of Cusco recognize the Sacsayahuaman archaeological park as being a karst landscape. Many cave systems are made in limestone bedrock and the sample was from this sort of cave. However, this cave was worked on by people in the past as is clear by the photos above.

The Vitrified Surface of the stone shows a very different spectrum of elements to the limestone body. The glaring difference is that Silicon is the predominant component with much higher concentrations. The trace elements of Aluminum and Magnesium are also significantly higher than the body of the stone. Oxygen is also present in double the quantities found in the body. The quantities of Calcium and Carbon are much lower than the body sample.

The Silicon, Aluminium and Magnesium seem to indicate that a material was added to the surface of the stone. The oxygen may have been part of this matter or it may have been introduced as part of oxidation during an aerobic heating process. This could have been during the formation of silicate, SiO2.

The analysis of the intermediate region between the surface and body of the stone shows a gradation of compositions. This is a surprising result, it implies either the surface layer was somehow ground and mixed with the body of the stone. The body limestone somehow merged/melted with the surface layer. Lastly and most unlikely, the limestone constituents could have been a part of the added surface layer. If this last one were true the second and third spectra would have been more similar.