Galaxite

Galaxite, also known as 'mangan-spinel' is an isometric mineral belonging to the spinel group of oxides with the ideal chemical formula MnAl₂O₄.

Galaxite is the manganese (Mn) rich endmember of the aluminium (Al) series of the spinel group. Divalent iron (Fe) and magnesium (Mg) readily substitute for the manganese in the crystal structure. Trivalent iron may also substitute for the aluminium. Thus, reflecting most natural samples, the formula may be better represented as (Mn,Fe,Mg)(Al,Fe)₂O₄.