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.
Curium-242 and curium-244 are used in the space program as a heat source (from the heat they generate as they undergo radioactive decay) for compact thermionic and thermoelectric power generation. Curium has not been found to occur naturally; it was the third transuranium element to be synthesized.