Curium hydroxide Cm(OH)3 is a radioactive compound first discovered in measurable quantities in 1947.

It is composed of a single curium atom and three hydroxy groups.

It was the first curium compound ever isolated.

[3][4] Curium hydroxide is an anhydrous colorless[2] or light-yellow[5] amorphous gelatinous solid that is insoluble in water.

[1] Due to self-irradiation, the crystal structure of 244Cm(OH)3 decomposes[clarification needed] within one day (244Cm has a half-life of 18.11 years); for 241Am(OH)3 the same process takes 4 to 6 months (241Am has a half-life of 432.2 years).