結晶のモルフォロジーからみたbiocrystallizationにおけるnormal growthとabnormal growth

抄録

Morphologies of single crystals (ployhedral, hopper, dendritic) and cryatal aggregates (spherulitic) are determined by the interface roughness and its anisotropy, driving force for crystal growth (supersaturation, super-cooling), and environmental conditions. Morphologies of crystals will be different between the cases where free growth is allowed and where growth is constrained by the environmental factors. Based on this, morphological characteristics of crystals and crystal aggregates of natural minerals and those formed by biocrystallization are compared. It is noticed that crystals formed by abnormal growth (such as gall stones, urea stones) take morphological characteristics of freely grown crystals (e. g. spherulitic), whereas those formed by normal growth (such as apatite in bone and tooth, aragonite and calcite in shells) do not show such morphologies. As possible constraining factors, 1) co-operative growth of organic and inorganic matters, and 2) growth in small enclosed environment, are mentioned.