If an olivine liquid containing 50 weight % forsterite (fig. 8.9) were cooled slowly until it was 50% crystallized, and then all of the crystals were separated from the liquid (perhaps as a result of crystal settling) what composition would the remaining liquid have (use the lever rule)?

0.35 weight fraction is liquid Forsterite and 0.65 weight fraction is liquid Fayolite

Explanation:

The lever rule is typically used to calculate the weight fractions of phases in a binary equilibrium phase diagram. It is also used in the estimation of the fraction of solid and liquid phases for a specific binary composition and temperature condition existing between the solid and liquid lines. Therefore, using the Figure. 8.9 and the use of lever rule, the composition of the remaining liquid would be 0.35 weight fraction of liquid Forsterite and 0.65 weight fraction of liquid Fayolite.