Light magnesium oxide is produced via lower temperature calcination of magnesium carbonate or magnesium hydroxide. The lower calcination temperature causes the calcined magnesia to have a lower density, so it is considered “light” compared to the denser high temperature calcined magnesia in heavy magnesium oxide. Light magnesium oxide derives its utility from its caustic nature when reacted with other metals, and for its higher potential for electrical conductivity. Light magnesium oxide is used primarily in applications that do not have restrictions on its overall mass, as its lower density means that it is more difficult to collect any significant mass of magnesium oxide in a container. However, despite its “fluffier” nature, light magnesium oxide is ideal for use in water treatment applications. Specifically, light magnesium oxide is used for extracting heavy metal contaminants from drinking and wastewater due to to its higher reactivity and larger overall surface area. By and large though, heavy magnesium oxide is preferred for industrial and manufacturing use, particularly where space is at a premium such as concrete or wallboard manufacturing.