Fabrication of Single Crystalline Calcite Needle Like Particles
Calcium carbonate CaCO3 occurs in two major polymorphs rhombohedral calcite and orthorhombic aragonite the latter is thermodynamically metastable In this study we first prepared aragonite needle like particles by introducing CO2 containing gas into Ca OH 2 aqueous slurry Then the resulted aragonite particles were heat treated at 500 °C for 1 h in
Structure proprits et minralisation de la coquille de l œuf
The eggshell of the hen is a highly ordered and mineralized structure which is sequentially deposited within an acellular milieu the uterine fluid secreted by the distal oviduct Each day the hen exports a huge amount of calcium to form the eggshell and undergoes tremendous changes in its calcium metabolism The eggshell results from spherulitic crystal