Human Resonance: Magnetic Earthenware of the Hummingbird Pyramid
Channel: humanresonance
Date: 2015-04-24

Magnetic earthenware pot sherds from the Hummingbird Pyramid's upper walkways contain finely pulverized quartz, tourmaline, pyrite, nickel, iron and laterite inclusions that reflect the sunlight.
http://www.human-resonance.org/magnetic_earthenware.html