percussion figure[pər′kəsh·ən ‚fig·yər]
Radiating lines on a crystal section produced by a sharp blow.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
an arrangement of cracks on the face of a crystal, formed by the sharp impact of the blunted point of a steel center punch. The shape of a percussion figure reflects the symmetry of the crystal and the anisotropy of the crystal’s tensile strength.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.