Comparative study of Fe2B3O7 and Mn4(B6O13(OH)): a new structure linking melilite and johachidolite

Abstract

Abstract The two compounds Fe2B3O7 (a = 663.61(4), c = 438.39(3) pm, space group: P 4 ‾ $\overline{4}$ 21 m) and Mn4(B6O13(OH)) (a = 445.14(1), b = 683.56(2), c = 1330.34(3) pm, β = 90.42(1)°, space group: P21/c) were synthesized under high-pressure/high-temperature conditions of 9 GPa and 800 °C. Their crystal structures have been determined via single-crystal X-ray diffraction and the occurring side-phases have been identified. Fe2B3O7 crystallizes in the melilite structure type, whereas the novel structure of Mn4(B6O13(OH)) can be derived from the structures of the minerals melilite or johachidolite.