For a crystal fractionally melting in a Solid Solution Phase Diagram, beginning with a 50% rock.
Imagine the system beginning with 40% anorthite which cools and crystallizes to 1400o. What will be the composition of the two fractions?
Answers: The Na rich fraction will have a composition of about 33% anorthoside (67% albite), and the Ca rich fraction will have a composition of about 74% anorthite.