Crystal structure and magnetic properties of Mn substituted ludwigite Co3O2BO3

► High quality single crystals of Co3−xMnxO2BO3 ludwigite were synthesized. ► Orthorhombic crystal symmetry with Pbam space group was found. ► Mn ions were found to prefer the octahedral positions 4. ► Spin-glass magnetic ordering was found below TN=41 K. ► Properties are discussed in comparison with ones for Co3−x FexO2BO3 compound.