Preparation of (NH4)2SO4 monocrystals

The preparation of (NH₄)₂SO₄ crystals has been studied, and the difficulties, especially the formation of numerous parasitical crystals and the irregular growth are discussed from a theoretical point of view and with regard to the performed investigations. Further on the habit of crystals and an acceptable procedure for the growing of homogeneous regular crystals are given. Likewise the effect of temperature, of P(H) of the crystallizing solution, the choice of seed crystals and the admixture of glycerine are reported.