Thulium(III) hydroxide is an inorganic compound with the chemical formula Tm(OH)3. Chemical properties Thulium(III) hydroxide reacts with acids and produces thulium(III) salts: Tm(OH)3 + 3 H+ → Tm3+ + 3 H2O Thulium(III) hydroxide decomposes to TmO(OH) at elevated temperature. Further decomposition produces Tm2O3. References Thulium compounds Hydroxides