Galena is by far the most abundant ore of lead and has been smelted for centuries to produce this soft, versatile metal. The United States is one of the leading producers of lead in the world, with prominent mines in Colorado, Idaho, Kansas, Missouri and Illinois (the town of Galena, Illinois, was named after this mineral). Lead has been used, for better or worse, as a pigment in paint, an additive in gasoline, in pipes for transporting water, as shielding from radiation, in glassware and in car batteries.
Galena forms sharp isometric crystals (usually cubes), has a metallic, steel-gray luster, perfect cleavage in three directions and its lead content gives it a very high density, making it one of the most easily recognizable minerals on earth. It has the chemical composition lead sulfide (PbS) and is found in hydrothermal deposits, where it is often associated with other important economic minerals, such as zinc, antimony, copper, iron and nickel ores. Silver can sometimes substitute for the lead in galena, making galena an unexpected source of silver.
Although galena is the most common ore of lead, there are many other lead-bearing minerals. Cerussite and anglesite are lead carbonate and lead sulfate respectively, and they form beautiful, surprisingly transparent, tabular crystals. The density of these minerals is very high for light colored minerals. These, and many other lead minerals, form as secondary alteration products of the primary ore, galena.
To learn more about minerals, come visit the Dice Mineralogical Museum on the first floor of North Hall, open Wednesdays, Thursdays and Fridays from 12:30 p.m. to 4 p.m.