Galena, Illinois for mayor and aldermen on May 24, 1841, replacing the board of trustees; Charles S. Hempstead was elected the first mayor with 185 of the 356 votes cast. The first census was also held that year, finding 1,900 inhabitants. By 1845 Galena was producing nearly 27,000 tons of lead ore and Jo Daviess County was producing 80 percent of the lead in the United States. Once one of the most important cities in the state, Galena was a hub on the Mississippi River between St. Louis and St. Paul. Due to erosion, the Galena River is now inaccessible to steamboats.
Mineral Rock forming minerals – typically silicates or occasionally carbonates – have a specific gravity of 2.5–3.5. High specific gravity is a diagnostic property of a mineral. A variation in chemistry (and consequently, mineral class) correlates to a change in specific gravity. Among more common minerals, oxides and sulfides tend to have a higher specific gravity as they include elements with higher atomic mass. A generalization is that minerals with metallic or adamantine lustre tend to have higher specific gravities than those having a non-metallic to dull lustre. For example, hematite, FeO, has a specific gravity of 5.26 while galena, PbS,