Habit modification of epsomite in presence of urea

The pure and urea doped epsomite (MgSO4·7H2O) crystals were grown at low temperature by the slow cooling technique. The effect of pH on the growth rate of pure MgSO4·7H2O was studied. It was found that the higher pH values increased the growth rate and the size of the crystals. The quantity of urea present in the doped magnesium sulphate crystals was estimated. The incorporation of urea into the mother solution was found to promote the growth rate. The habit of the crystals changed from orthorhombic to tetragonal. Further, there was an increase of microhardness of the crystals on doping of urea.