For a crystal fractionally melting in a Solid Solution Phase Diagram, beginning with a 50% rock.
Imagine the system heats up to 1350o at which point it fractionates. What will be the composition of the two resulting fractions?
Answers: The Na rich fraction will have a composition of about 22% anorthoside (78% albite), and the Ca rich fraction will have a composition of about 66% anorthite.