Vicinal Form

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Vicinal Form

 

vicinal pyramid, a gradually sloping pyramidal hill or depression on the surface of a crystal. It is formed during the growth of the crystal, and according to dislocation theory, it arises on the surface at the point where the spiral dislocation emerges. The form of the vicinal pyramid corresponds to the symmetry of the crystal facet; vicinal pyramids of various shapes are characteristic of different facets, making it possible to determine the crystal symmetry with the aid of the vicinal facets, as well as according to the shape of the etched figures.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.