“Reflected light digital image (1 mm wide) of a colloform aggregate of native arsenic (bright) The interstitial minerals are proustite (light-blue), argentopyrite (light-brown), chalcopyrite (yellow) and sphalerite (grey). Reference: Grundmann, G. (1971): Neues über Silbererze vom Tannenbodengang bei Wieden (Südschwarzwald). Der Aufschluss Volume 22, No. 6/1971, p. 195-200. G. Grundmann collection and photo. ”

“Reflected light digital image, partly crossed polarizers (1 mm wide) of a colloform aggregate of native arsenic (bright) The interstitial minerals are proustite (crimson red internal reflectance), argentopyrite (light-brown, cream), chalcopyrite (yellow) and sphalerite (grey).. Reference: Grundmann, G. (1971): Neues über Silbererze vom Tannenbodengang bei Wieden (Südschwarzwald). Der Aufschluss Volume 22, No. 6/1971, p. 195-200. G. Grundmann collection and photo. ”