The structure and mechanism of growth of calcium carbonate minerals in early stages of shells of the oyster Crassostrea Virginica
| Autor: | DoSuk Duke Lee |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Calcite
Oyster biology Aragonite Nucleation Mineralogy engineering.material Condensed Matter Physics Bivalvia biology.organism_classification Inorganic Chemistry chemistry.chemical_compound Crystallography Calcium carbonate chemistry biology.animal Materials Chemistry engineering Carbonate Eastern oyster |
| Zdroj: | Journal of Crystal Growth. 102:262-268 |
| ISSN: | 0022-0248 |
| Popis: | In this paper, the nucleation and subsequent growth of the solid mineral phases of calcium carbonate (CaCO 3 ) in shells of the common eastern oyster Crassostrea virginica were investigated. Cross-polar analysis under the optical microscope demonstrated that mineralization began as early as 18 h post-fertilization. During early stages of the shell development the most prominent structural feature of the shell was the spherulitic orientation of minerals with their a -axis parallel to the radius of the shell. Electron microdiffraction was applied for the first time to the determination of the structure and orientation of the shell crystals. Single-crystal microdiffraction patterns showed the aragonite phase of CaCO 3 to be arranged in a manner such that (0 k 0) lattice planes were parallel to the circumference of the shell. Examination of more mature stages of shell development showed the appearance of calcite phase (with the c -axis of these crystals inclined at a 44° angle from the surface of the nacre in a direction towards the outer rim of the shell). These crystallographic studies of oyster shell formation suggest that the spherulitic arrangement of minerals observed in larva may act as a template for crystals to form during subsequent stages of shell development. |
| Databáze: | OpenAIRE |
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