How much magnesium is present in Earth’s crust?

Magnesium is the eighth most abundant element in Earth’s crust, with estimates of its concentration ranging from approximately 2.4 to 2.5 percent.12

Because of its strong reactivity, magnesium does not occur in a free or native state in nature. Instead, it is found in a wide variety of compounds, including carbonates such as dolomite and magnesite, as well as various silicates and other minerals. Beyond its presence in the Earth's crust, magnesium is also widely distributed in seawater, which serves as a significant and nearly inexhaustible source for magnesium processing.12