Aluminum hydroxide is an antacid used to treat acid indigestion and reduce phosphate levels in people with kidney problems. Learn about its dosage, interactions, side effects, and precautions before taking it. Learn about aluminium hydroxide , an amphoteric compound that occurs naturally as gibbsite and has various applications. Find out how it is produced, reacts, and decomposes in different conditions. Aluminium hydroxide is also known as aluminium acid, aluminium hydroxide , or aluminium (III) hydroxide . It occurs naturally in the mineral gibbsite and its polymorphs, namely dolerite, nordstrandite, and bayerite. Chemistry Aluminium HydroxideAluminium Hydroxide Aluminium hydroxide , also known as hydrated alumina, is a chemical compound with the formula Al (OH) A 3. It is a white, gelatinous solid that is insoluble in water. Aluminium hydroxide is amphoteric, meaning that it can react with both acids and bases. Properties Chemical formula: Al (OH) A 3 Molar mass: 78.00 g/mol Appearance: White, gelatinous solid Density: 2.42 g/cm3 Melting point: 300 °C (572 °F) Boiling point: 2,000 °C (3,632 °F ...