Synthetic efforts have identified a growing number of classes of organic macro-molecular impurities. Inclusion of an organic phase is believed to play a key role in enhancing the mechanical properties of the crystals, which are believed to share structural features with biogenic minerals and to have both increased hardness and fracture toughness relative to their pure, geological counterparts. Using a variety of techniques, including X-ray diffraction and infrared spectroscopy, the researchers demonstrated that the incorporated micelles lead to an increase in the level of atomic disorder at the inorganic-organic interface and to a compressive-strain gradient in the calcite lattice. The incorporation of organic materials into a crystal host is a non-equilibrium process that strongly depends on kinetic, entropic and enthalpic constraints, as well as on physicochemical variables, including the occlusions' size, shape, surface chemistry and possibly rigidity.