The domain structure of the ferroelastic crystal K2Cd2(SO4)(3) was obs
erved and investigated in detail, in different temperature regions bel
ow T-c using a polarizing microscope. It is shown that the appearence
of a domain structure depends on crystal thickness and the domain stru
cture can have a time dependent dynamic. The orientation of the domain
walls in potassium-cadmium langbeinite crystals has been determined.