Onion morphology and microstructure of polyhedral serpentine
Résumé
We describe the shape and internal structure of polyhedral spheroids found in serpentinized peridotites. Serpentine spheroids resemble geodesic domes made of ~160 to 180 triangular facets. At facet edges, the nested layers bend by ~14° along their three <010> crystallographic directions, resulting in an onion-like structure with lateral continuity of the layers. The stacking of the serpentine layers within sectors is controlled by interlayer bonding. These polyhedral onions correspond to a novel type of spherical nanostructure for layered materials