https://www.academia.edu/56764408/The_mirror_the_magus_and_more_reflections_on_John_Dees_obsidian_mirror
The obsidian mirror associated with the Elizabethan polymath and magus John Dee (1527–1608/1609) has been an object of fascination for centuries. The mirror, however, has a deeper history as an Aztec artefact brought to Europe soon after the Spanish conquest. The authors present the results of new geochemical analysis.