At http://westerndigs.org/mesoamerican-fools-gold-mirrors-found-in-arizona-… … a link between Arizona and central Mexico in pre colonial times has been established by various artefacts. The latest exmaples are some 50 mirrors encrusted with the brillian mineral pyrite – known as Fools Gold (but herewith a gold substitute). They were found in a former settlement of the Hohokum Culture and probably arrived in Arizona by trade rather than migration. However, ceremonial ball courts have also been found, and copper bells and the remains of a macaw (bird). Why the link with Arizona?
It seems the mirrors were made in Mexico. They were worn by the elite, hung around the kneck. They have been C14 dated between 650 and 950AD – so it isn't entriely unreasonable to assume they were the product of trade (or migration).