Curium is highly radioactive. As a metal, it is lustrous and silvery. It is malleable, chemically reactive and electropositive. Its surface rapidly oxidizes in air, gaining a thin film. In dilute solutions, it dissolves rapidly to form Cm (III) solutions. Curium metal exists in two crystal structures: a double-hexagonal close-packed and a high temperature, face-centered cubic close-packed. [See Periodic Table of the Elements]
Divalent compounds of curium have never been observed to form in bulk. Most compounds of trivalent curium are stable and faintly yellow or yellow-green. Because curium isotopes are available in large quantities, many curium compounds have been prepared and characterized. The majority of compounds are in the trivalent state.
If absorbed in to the body, curium accumulates in the bones. Its radiation destroys red blood cell formation. Consequently, curium is considered very toxic.