Transformation toughened zirconias such a Magnesia-Stabilized Zirconia have small precipitates of tetragonal phase which are formed inside of the cubic phase grains. These precipitates transform from the meta-stable tetragonal phase to the stable monoclinic phase when a crack attempts to propagate through the material. This causes the precipitate to expand and blunt the crack tip promoting toughness.
MSZ can be either ivory or yellow-orange in color due to differences in preparation of the raw material.Ivory colored MSZ has a higher purity and offers slightly better mechanical properties.