Uranium ore support a neutron-mediated chain reaction). Uranium, thorium, and potassium are the main elements contributing to natural terrestrial radioactivity. Uranium has the highest atomic weight of the naturally occurring elements and is approximately 70% denser than lead, but not as dense as tungsten, gold, platinum, iridium, or osmium. It is always found combined with other elements. Along with all elements having atomic weights higher than that of iron, it is only naturally formed in supernova explosions. The primary uranium ore mineral is uraninite (UO) (previously known as pitchblende). A range of other uranium minerals can be found in various deposits. These
Galena, South Dakota A Bear Butte Creek runs beside the town, which is located in a meadow in the middle of a gulch. Galena, South Dakota Galena (also Galena City) is an unincorporated community in Lawrence County, South Dakota, United States. It is often considered to be a ghost town, even though a few families still live in the area. It is not tracked by the U.S. Census Bureau. The town was named after the galena found in the ore in the surrounding mines. In 1875, gold was discovered in the Black Hills and drew settlers to the area. The mines in the