Galaxite, also known as 'mangan-spinel' is an isometric mineral belonging to the spinel group of oxides with the ideal chemical formula Mn2+Al2O4.

It occurs associated with alleghanyite, rhodonite, sonolite, spessartine, tephroite, kutnohorite, manganhumite, jacobsite, kellyite and alabandite in the Bald Knob area.

Associated minerals include katoptrite, magnetite, manganostibite, magnussonite, tephroite, manganhumite and manganosite in the Brattfors mine area of Nordmark, Värmland, Sweden.

[3] 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.