Magnetite Sphere
Transmitted Crossed Polarized Light Illumination

Magnetite is a reasonably good conductor of electricity for a semiconductor. As a result it is a good
reflector and when viewed between cross linear polarized filters light can be seen at the edge of the
sphere in each of the four quadrents. Soot, cenospheres, toner, spores and other non-conductive black
particles do not exhibit this effect.