More than 90 percent of the mineral composition of the Earth's crust is composed of silicate minerals. These silicate minerals differ with each specific compound, as each compound is composed of different elements to form the types of rock that constitute the Earth's crust.
Aside from silicate minerals, less than 10 percent of the Earth's crust is composed of nonsilicate minerals such as sulfides and oxides.
The most common type of silicate mineral rocks is known as feldspar. Feldspar is a collective name for rocks that contain the mineral silica to some extent. Plagioclase, for example, is the most common type of feldspar found in the Earth's crust, composing as much as 39 percent of the Earth's crust, according to Sand Atlas.