Both conventional and nano silicate minerals have importance for several fields of advanced technological research and industries. Nano clay can be used as filler material or reinforcement for other materials to produce nanocomposite as the case of clay based-polymer nanocomposite. Nowadays there is worldwide interest of these materials which may be synthesized or natural. In current paper, shrinkage phenomenon has been studied and cracks of this material using natural Saudi Arabian smectite type MMT. The three dimensional changes of cubic samples of nano clay are studied and compared to conventional clay, semi conventional-semi nano clay and another cementous type of clay based nanocomposite. It is found that nano clay changes are very sensitive and high without cracking while conventional clay type has less change accompanied by cracks. On the other hand semi conventional-semi nano clay mineral composite has intermediate resuls of volume change with cracks but less than the pure conventional type. SEM, EDAX and XRD characterizations are made. Both volume and length changes are recorded. The study can be considered as the base of proposing of new swelling – shrinkage theory.