Galena cubic unit cell much like the mineral halite of the halide mineral group. Zinc, cadmium, iron, copper, antimony, arsenic, bismuth and selenium also occur in variable amounts in galena. Selenium substitutes for sulfur in the structure constituting a solid solution series. The lead telluride mineral altaite has the same crystal structure as galena. Within the weathering or oxidation zone galena alters to anglesite (lead sulfate) or cerussite (lead carbonate). Galena exposed to acid mine drainage can be oxidized to anglesite by naturally occurring bacteria and archaea, in a process similar to bioleaching. One of the oldest uses of galena was
Galena, Illinois top-ten "Charming Small Towns". Galena is located at (42.418171, −90.431472) along the Galena River, which is one of many tributaries of the Mississippi River. According to the 2010 census, Galena has a total area of , of which (or 99.83%) is land and (or 0.17%) is water. Galena is located in the Driftless Zone, an area that was not covered by glaciers during the recent ice ages. This area, which includes the far northwestern corner of Illinois, escaped glaciation, while almost the entire state was glaciated, nearly to its southern tip. Because it escaped glaciation, this area is known for