Echinoderm calcite: single crystal or polycrystalline aggregate.
Electron microscopy of natural and broken surfaces of echinoid skeletal plates reveals that the interior portions have the morphology of a single crystal, whereas the exterior is a polycrystalline aggregate with preferred orientation. These data help to resolve earlier contradictory x-ray and optical evidence.
D000818:Animals; D002119:Calcium Carbonate; D003461:Crystallography; D004447:Echinodermata; D008854:Microscopy, Electron
D002119:Calcium Carbonate