3. Geochemistry, mineralogy, resources, reserves and deposits

Germanium does not exist as a native metal or in specifically Germaniferous minerals, with the exception of agutite GeO ₂ , which is a rare mineral. It is a dispersed element, found in trace amounts in base metal minerals where it is present in the crystal lattice as a result of substitutions with As, Ga, Si, Sn, Zn, etc. Germanium is also present in coal, where it is associated with organic matter rather than a mineral component ( , ). It seems to be concentrated...