Nickel hydroxide is an inorganic compound, known by the formula Ni(OH)2 or Nickel(II) hydroxide. It is an odorless, apple green, crystalline solid usually available in powder form. Nickel hydroxide occurs naturally as the mineral theophrastite. It is electroactive and is converted to Ni(III) oxy-hydroxide in response to electrical stimuli. It is insoluble in water and dissolves readily in acids and ammonium hydroxide. It is non-explosive and non-oxidizing under normal conditions. It has a melting point of 2300C and decomposes before melting at 2000C. Its autoignition temperature or flash point is 4000C. It is denser than water having a density of 4g/cm3.