<p>Pure and manganese (Mn) doped magnesium sulphate heptahydrate (MSH) crystals, by changing the mol.% of Mn, were grown by solution growth technique at normal room temperature. The grown crystals were characterized by various characterization techniques such as elemental analysis, Raman analysis, thermal analysis, dielectric spectroscopic analysis, ac conductivity analysis and modulus spectroscopic analysis. The elemental analysis confirmed the presence of Mn in the crystal lattice of pure MSH. Raman analysis showed the presence of characteristic vibrations of sulphate (SO₄) group in pure and Mn doped MSH crystals. Mn doping resulted into increase in peak intensity of SO₄ group. The thermal study showed strong bonding of water molecules with the crystal lattice of Mn doped MSH crystals. Kinetic and thermodynamics parameters were evaluated and showed thermodynamically unstable, non-spontaneous and endergonic process of dehydration of pure and Mn doped MSH crystals. Dielectric study showed the normal dielectric behavior of pure and Mn doped MSH crystals. Mn doping resulted into increase in dielectric constant and loss values. The ac conductivity analysis showed increased conductivity of Mn doped MSH crystals following Jonscher power law. Modulus study showed grain and grain boundary relaxation mechanism in the pure MSH crystal, while dominant effect of grain relaxation mechanism in the Mn doped MSH crystals. The stretch exponent parameter showed non-Debye relaxation mechanism in the pure and Mn doped MSH crystals.</p>