Erbium(III) hydroxide is an inorganic compound with chemical formula Er(OH)3.
Erbium(III) hydroxide reacts with acids and produces erbium(III) salts:
Er(OH)3 + 3H+ → Er3+ + 3H2OErbium(III) hydroxide decomposes to ErO(OH) at elevated temperature. Further decomposition produces Er2O3.