Bowen's Reaction Series

In the early part of the 20th century, N. L. Bowen carried out experiments to characterize the process of crystallization of igneous rocks from magma. The illustration below is patterned after Lutgens and Tarbuck's perspective of that reaction series.

The difference in crystallization temperature for the different kinds of minerals plays a major role in the differentiation of rock composition as the magma cools.