However, this "painted mountain" is notoriously difficult to find and get to, requiring several days of hiking to reach its peak deep within the Andes by way of Cusco. The painted Ausangate mountain is also considered to be holy and believed to be the deity of Cusco by local Peruvians. Every year thousands of Quechua pilgrims visit the Ausangate Mountain for the Star Snow festival which takes place a week before the Corpus Christi feast. This produced significant volcanism and the introduction of rare and varied mineralogy to the Andes Mountains. The reason we see the rainbow coloration in the stratigraphic layers of the Ausangate mountain is largely due to weathering and mineralogy.

Source: Forbes January 21, 2017 17:31 UTC