Asset Overview
Structure of the mineral plagioclase. Shows a 2 x 2 x 2 supercell of an idealized albite structure, with Na (or Ca) in pink, Al in silver, Si in ochre, and O in red. The framework structure of feldspar can be seen. (Plagioclase is a solid solution, with some atoms being Na and some atoms being Ca. To accommodate their different charges, when Ca substitutes for Na, a coupled substitution of Al for Si also occurs.)