Hallo,
in den Links sehe ich zwar Germanit aber nicht die gesuchten Germantikristalle.
Nach Melcher *) dürfte es schwer sein da überhaupt ein Foto zu machen: "Most abundant are germanite and reniérite, which usually occur as small (10 to 100 μm) anhedral to subhedral crystals in association with tennantite, galena, sphalerite, bornite, chalcopyrite, digenite, pyrite and enargite. Germanite was present in the Tsumeb pipe from the surface down to 31 level, whereas reniérite is only known below level 15."
Gruß
Berthold
*) Melcher, F. (2003) THE OTAVI MOUNTAIN LAND IN NAMIBIA: TSUMEB, GERMANIUM AND SNOWBALL EARTH. MITT.ÖSTERR. MINER. GES. 148 S. 413-435