Stilpnomelane, Actinolite, Chlorite Group
Talcum works, Schwarzenbach an der Saale, Hof District, Upper Franconia, Bavaria, Germany
Leafy stilpnomelane crystals in association with actinolite (blue-green, bottom left), partially replaced by chlorite (green, middle) in albite gneiss. The horizontally oriented crystals show an orange-brown pleochroism, the diagonally and vertically oriented crystals show a dark brown pleochroism.
Thin section, transmitted plane polarized light ...
© Günter Grundmann, Detmold