Some other compositions with the melilite structure include: alumoåkermanite (Ca,Na)2(Al,Mg,Fe2+)(Si2O7), okayamalite Ca2B[BSiO7], gugiaite Ca2Be[Si2O7], hardystonite Ca2Zn[Si2O7], barylite BaBe2[Si2O7], andremeyerite BaFe2+2[Si2O7]. Some structures formed by replacing one oxygen by F or OH: leucophanite (Ca,Na)2(Be,Al)[Si2O6(F,OH)], jeffreyite (Ca,Na)2(Be,Al)[Si2O6(O,OH)], and meliphanite (Ca,Na)2(Be,Al)[Si2O6(OH,F)].