Difference between magnesium oxide

Magnesium oxide is an inorganic substance with the chemical formula MgO. It is an oxide of magnesium and an ionic compound. It is a white solid at room temperature. Magnesia exists in nature in the form of periclase and is the raw material for magnesium smelting.
Magnesium oxide has high fire resistance and insulation performance. After high temperature burning above 1000 ℃, it can be transformed into crystal. When it rises to 1500 - 2000 ° C, it will become dead burned magnesium oxide (magnesia) or sintered magnesium oxide.
Magnesium hydroxide is an inorganic substance with the chemical formula Mg (OH) 2, white amorphous powder or colorless hexagonal column crystal. It is also known as caustic magnesite and light burned magnesia. It is soluble in dilute acid and ammonium salt solution, but difficult to dissolve in water and alcohol. The suspension in water is called magnesium hydroxide emulsion. The part dissolved in water is completely ionized, and the aqueous solution is weakly alkaline and almost insoluble in water. When heated to 350 ℃, it loses water to form magnesium oxide and magnesium hydroxide. Brucite, a natural mineral, can be used for sugar making and magnesium oxide. Because magnesium hydroxide is rich in nature and its chemical properties are similar to aluminum, users began to use magnesium hydroxide instead of aluminum chloride for deodorant products. It is used as analytical reagent and also in pharmaceutical industry.