Christy, A.G. and Grew. E.S. (2004) Synthesis of beryllian sapphirine in the system MgO-BeO-Al2O3-SiO2-H2O and comparison with naturally occurring beryllian sapphirine and khmaralite. Part 2: a chemographic study of Be content as a function of P, T, assemblage and FeMg-1 exchange. American Mineralogist 89, 327-338