Coccydynia is often caused by an injury, but it may occur seemingly spontaneously. There are many causes of tailbone pain that can mimic coccydynia, including sciatica, infection (including shingles of the buttocks), pilonidal cysts, sacroiliitis, and fractured bone (broken tailbone or tailbone fracture).
Characteristics: Curium is a hard, dense radioactive silvery-white metal. It tarnishes slowly in dry air at room temperature. Most compounds of trivalent curium are slightly yellow in color. Curium is highly radioactive and it glows red in the dark.
According to the International Union of Pure and Applied Chemistry or IUPAC, the term heavy metal may be a  meaningless term  because there is no standardized definition for a heavy metal.Some light metals or metalloids are toxic, while some high-density metals are not.xamples of heavy metals include lead, mercury and cadmium. Less commonly, any metal with a potential negative health effect or environmental impact may be termed a heavy metal, such as cobalt, chromium, lithium and even iron.